It was obvious this was their first visit to Washington. The three tourists, waiting for an elevator in the Capitol, puzzled over the "Members Only" sign and then one, in all seriousness, asked, "How much does it cost to join?"

Tourists aren't the only ones baffled by Congress. Experienced legislative professionals, including Hill staffers, can be stumped by procedures and find it difficult to follow (much less predict) congressional action.

So herewith a primer for tracking Congress, aimed at both beginners and the battleworn. (And you might want to pass it on to the more serious-minded friends and relatives about to descend upon you.)

During the first few months of every Congress, the introduction of new legislation produces considerable commotion. Floor speeches, news conferences and other publicity accompany most proposals, many of which are retreads from previous sessions. The bill's sponsor may achieve instant fame as he speaks before organizations supporting the measure.

Except for this drummed-up sense of activity, little else will result from formal introduction of most bills. Ninety-five percent will die at the end of the next years.

It's not unusual for members to "reserve" attention getting bill numbers. Advocates, for example, of faster tax deductions for business investments -- specifically a 10-year depreciation schedule for buildings, five years for equipment and three years for automobiles -- have reserved bill number HR 1053.

Certainly many legislators have their own projects, but individual concerns often are triggered by a constituent or special-interest group.

Then there is the case of Sen. David Pryor (D-Ark.), who, while sharing a taxicab with two strangers, overheard them discussing whether they should charge the government $10,000 or $25,000 for a study. This episode served as the catalyst for Sen. Pryor's introduction of the "consultant reform act."

The Congressional Record contains many clues about the origin of legislation. Buried in each day's issue is a long list of new House bills. It lists bill numbers, sponsors, brief titles and committees to which they have been referred.

The real utility of the Congressional Record is, of course, to review Senate bills. Senators almost always include a statement summarizing provisions of the legislation, actual text, and a note of thanks to the appropriate lobbying or trade group for contributing to its drafting, thus revealing the positions of these special interests.

For example, Sen. Charles Mathias (R-Md.) introduced legislation (S2) eliminating the so-called "marriage penalty tax." Besides a statement arguing for modification of the tax code Mathias lists, in the Jan. 5, 1981, Record, support for the measure by the Family Service Association, the National Taxpayers Union, Women's Equity League and others.

Since most bills are stillborn, how does one figure which are likely candidates for serious consideration? Usually, proposals introduced by any subcommittee or committee chairmen will be far in front.

Most of the anticipated steady stream of bills from the Reagan administration have a strong chance of advancing. As agents of the president, senior Republican members will drop proposals in the House hopper.

Occasionally, the legislator will want to put some distance between his or her position and that of the executive branch: You may see the words "by request" following the sponsor's name on the bill's front page.

The easiest way to discover what bills have been introduced formally is by calling the Legislative Status Office, located in the old FBI Building, now House Annex 2. Its computer memory goes back to 1973 and can quickly flash, let's say, whether there was any activity last year on handgun control legislation, whether any federal initiatives have been introduced yet in this Congress and what committees have jurisdiction.

The office can produce a free computer printout overnight. The main drawback is the office's popularity -- phone lines are often busy.

Call the appropriate committees to double-check the information you get from the Legislative Status Office and to find out whether hearings are scheduled.

Incidentally, any avid Congress-watcher needs a directory of the 97th Congress. You can compile your own for free. Committee rosters are available from the Clerk of the House and the Senate Secretary. Ask these offices for a summary of the jurisdiction of each committee so that you can follow those overseeing areas in which you are interested.

Don't forget the House and Senate Appropriation Committees. For example, if you want to monitor activity dealing with the Consumer Product Safety Commission, you should know who is on the Senate Appropriation Subcommittee on HUD-Independent Agencies and the Senate Commerce Committee. On the House side, the primary panels determining the scope of the commission's activities and budget are the Energy and Commerce Subcommittee on Health and Environment and the Appropriation Subcommittee on HUD-Independent Agencies.

The Capitol Hill switchboard can give you the phone numbers.

A well-defined timetable theoretically breaks each session into "seasons." This springs from the Congressional Budget Control and Impoundment Act of 1974 requiring that all standing committees -- except appropriation committees -- complete recommendations for all federal spending programs by May 15 each year.

The 97the Congress is now about two months behind schedule, primarily because of the Reagan administration's full-scale revision of President Carter's proposed budget for fiscal 1982.

Despite White House pledges to fill in details of the Reagan program within the first 100 days -- and congressional promises for prompt action -- Congress has a habit of missing target dates and deadlines. "I wander how long," Rep. Abraham Kazen (D-Tex.) once jeered, "it would take Congress to cook minute rice."

Now 60 to 100 daily committee hearings are typical. The dominant committee activity in April and May will be bill-drafting often called "markup sessions."

In the next "season," about June, the locus of activity shifts to the floor in both houses. There is usually only about two or three days' advance notice of bills on the House docket. Senate key committee staffers are apt to have about an hour's warning that "their" bill is slated for debate.

Rely on the House and Senate floor tapes and call the Republican and Democratic Cloakrooms for more scheduling details.

The most chaotic period stretches from Labor Day until about Halloween, sometimes lasting until Christmas. It is during this "fourth season" when House and Senate negotiators will be hammering out compromises -- perhaps on the president's tax-cut legislation -- and almost certainly, a dozen appropriation bills necessary to keep federal agencies and programs going.

As you work your way through the legislative labyrinth, remember.

Up to three dozen congressional staffers will work on most major bills.

Committee staffers work for the chairmen and may be guarded. But if you want a clear picture on a particular measure, you must have direct contact with these staff professionals, since they choreograph the bill's course.

Don't overlook minority committee staffers. In the House they work chiefly for the ranking Republican member, in the Senate, of course, the reverse. Unlike committee chairmen's aides, they usually are kept out of the spotlight and may be eager to predict, and pass on rumors. Since the GOP takeover in the Senate, you may find Democratic staffers who were too busy to talk last year quite accessible in their new minority roles.

Other resources:

Partly caucuses and the some 80 informal congressional coalition -- from the Congressional Mushroom Caucus to the Jewelry Manufacturing Coalition.

General Accounting Office (GAO) -- for reports on your subject, talk with the employe detailed to the issue.

Congressional Research Service (CRS) at the Library of Congress technically off-limits to the public, but relatively easy to get copies of its studies on a bewildering array of topics. You might try this approach.

(1) Play constituent: phone your Senator or Representative's office and ask a legislative assistant to find out what CRS reports are available. (2) Ask your member's office to get the reports you want.

National Referral Center another Library of Congress, subdivision which can guide you to private organizations and trade associations concerned with given topics.

Federal Information Center -- part of the General Services Administration, it can direct you to a government expert on any subject.

Congressional Quarterly and National Journal -- available at most libraries.

Special-interest groups -- ranging from the PTA to the NRA. Contract them for their newsletter many of which are free.

Major think tanks such as the American Enterprise Institute and the Brookings Institution.

The possibilities for tracking Congress are almost limitless.