This is one of those weeks when Congress plays with real money.

For all those who have been confused about the inscrutable, interminable congressional budget process and the seemingly aimless swarming of appropriations bills that never seem to land anywhere, there is one thing that makes this week stand out: Congress will have to come up with real dollars or the money pipeline to the govenment will run dry.

But, at the same time, it will still be juggling a dozen multibillion-dollar appropriations bills and groping its way through the budget maze--all in a kind of muddle-through fashion that bears little resemblance to what the textbooks say Congress should be doing.

By the end of the week, Congress hopes to have passed about half its 13 appropriations bills, enacted a "continuing resolution" to fund the rest of the government for as long as it takes to finish the appropriations job and found a respectable way to end its budget resolution miseries.

In a vastly oversimplified fashion, here's what's happened so far and the outlook for this week.

Congress started out the year in good shape, adopting a first budget resolution for fiscal 1982 (Oct. 1, 1981, to Sept. 30, 1982) that set spending and revenue targets to serve as guidelines for preparation of authorization and appropriation bills. Along the way, it also approved President Reagan's three-year program of spending and tax cuts, including $35 billion in spending reductions for the current fiscal year.

But, as summer ended, the administration, jarred by soaring interest rates and alarmed by rising deficit projections, prepared a second dose of fiscal medicine, including $13 billion in further spending cuts and $3 billion in tax increases (called "revenue enhancements" by the White House).

For this and other reasons, Congress started falling behind, which is nothing new for Congress.

First, as it has done before, it missed its Sept. 15 deadline for passage of a second budget resolution. This resolution--theoretically the final one for the year--is supposed to set binding spending ceilings after accounting for economic changes since passage of the first resolution.

This year the second resolution was, in effect, put on hold until Congress could figure out what to do with Reagan's latest budget proposals--a quest that still continues.

Then Congress missed the Oct. 1 deadline for passage of its 13 appropriations bills that fund the operations of goverment departments and agencies for the fiscal year.

Congress usually fails to meet this deadline for at least some of the money bills, necessitating a so-called continuing resolution for interim funding until the bills are passed.

This year, because not a single appropriations bill had been enacted by Oct. 1, Congress passed the granddaddy of all continuing resolutions, putting the entire government on stop-gap financing until Friday. By this time it hoped to have most if not all of its money bills sent to the White House for signature.

But Congress was balking at a key element of Reagan's program, which called for an $8.4 billion, or 12 percent across-the-board, cut in all domestic appropriations, and Reagan had not yet sent Congress details of the rest of the package.

Because the continuing resolution funded the government at levels costing about $1 billion more than Reagan wanted through this upcoming Friday, Reagan told government agencies to spend only at his pared-back levels and moved officially to defer the $1 billion in spending.

And, attempting to exert what leverage he could to force cutbacks in appropriations bills, Reagan vowed to veto any "budget-busting" money measures, a threat deliberately fuzzy enough to keep Congress guessing.

The House, meanwhile, had churned out most of its appropriations bills, and the Senate, after waiting for negotiations with the White House on a compromise budget-cutting package, finally started moving ahead. All but defense and foreign aid have passed one or both houses. Nearly half have at least reached a House-Senate conference. But none have been shipped off to Reagan for signature.

All the major bills, in both the Democratic House and Republican Senate, exceed Reagan's revised spending targets, although Congress and the administration disagree over how much.

It is a multibillion-dollar disagreement. Republicans on the Senate Appropriations Committee contend that the Senate has so far come up with $6.8 billion of the $8.4 billion savings that Reagan wanted.

But Reagan's Office of Management and Budget, using different criteria, says the Senate is still as much as $1 billion over his previous target, meaning $8-to-$10 billion over the new target. OMB contends the House is $11-to-$12 billion over the new target.

Still at issue is defense, which remains before the House Appropriations Committee. The administration has proposed a modest $2 billion cut from big growth planned for the Pentagon, but Congress may insist on more.

Although there will be an effort to wrap up five or six of the bills this week, it is unlikely that many will be signed into law before Friday.

But the bills are important because they will provide the basis for spending levels for the new continuing resolution, which will last until appropriations bills are passed or, if congressional leaders have their way, for the rest of the fiscal year for those programs that never win an appropration.

If the resolution's spending level turns out to be what Congress normally chooses--the conference compromise or the Senate or House bill, whichever is smaller--it may still be too rich for the administration's blood. So House Republicans are planning a floor fight today to pare the continuing resolution down to the point where it gives Reagan about half the $8.4 billion in domestic cuts that he wants.

If they fail, some Senate Republicans may make a similar effort, but Senate Appropriations Committee Chairman Mark O. Hatfield (R-Ore.) was reported last week as wanting to stick to existing Senate levels, and it was not clear whether the Senate leadership would try to buck him.

The continuing resolution is not expected to win final congressional approval until Friday. Then the question becomes whether Reagan vetoes it.

If he does, and if Congress does not override the veto, an impasse could--in theory at least--leave the country without a government to open on Monday morning, which, as one congressional aide put it, would be the ultimate budget cut.

Meanwhile, back on the subject of the long-lost second budget resolution, the issue is whether to put everything on hold until Reagan submits his 1983 budget program next January or to try to draft a resolution that reflects spending cuts and tax increases that would be necessary to provide a balanced budget by 1984--a goal Reagan has abandoned in order to protect his policy of pursuing economic recovery through tax cuts.

The House Budget Committee wants to wait; its Senate counterpart wants to move ahead but may not be able to agree on a way to do it.

In any case, Congress as a whole, bracing for an even more painful bout with budget-cutting next year, appears to have little stomach for starting the ordeal now.