The newly reorganized Loudoun County Board of Supervisors last week, in one of its first official acts of the new year, approved a formal resolution of appreciation for a visibly surprised County Administrator Philip Bolen.

Bolen, whose service to the county began 25 years ago as a schoolteacher, is entering his 15th year in his present post. The board offered the resolution, new chairman James Brownell said, because of Bolen's patience in providing so many different boards "with sound guidance" during years of change and growth in the county. Among other things, Bolen was credited with kindness and humor and was described as a man "who can be trusted rather than feared, is honest rather than clever, faithful rather than ambitious and forgiving rather than proud."

In other action the board authorized its staff to begin negotiations for the architectural and engineering design of a proposed fire and rescue training center and youth shelter to be built on a 92-acre site the county owns on Sycolin Road in Leesburg. The staff will negotiate with one Maryland firm and two Northern Virginia firms who qualified for consideration.

Adults dissatisfied with their jobs or unemployed because their jobs were eliminated through technological change may be retrained in a vocational training program being offered at the Charles Monroe Vo-Tech Center in Leesburg. Applicants must have either a high school diploma or its equivalent or be enrolled in a high school equivalency program. For information about schedules, classes and tuition, call 777-6770. Joint Ownership of Library Sought

The Loudoun County Board of Supervisors authorized county attorney Edward Finnegan last week to file a petition in Circuit Court that will convey joint legal title of the land on which the Purcellville Library sits to the county and the town of Purcellville.

The town is trustee for the land but the county, which owns and runs the library, cannot make improvements to it unless it owns or is trustee of the land as well. The county wants to expand the facility by building a new wing with part of the $6.5 million library bond approved by the voters in November 1984.

The old water tower in Purcellville was dismantled and towed away last week and the 6,500 square feet on which it sat has been traded rather than sold.

According to Town Manager William Dennis, resident William Whitmore now owns the parcel. In exchange, Whitmore gave the town 20 acres near the watershed on Short Hill mountain that separate two tracts of land owned by the town.

The trade gave Purcellville officials an easement if it ever becomes necessary to run water pipes between the two tracts, Dennis said. The council rejected two bids for the water tower property in October because, it said, the bids were not anywhere near what officials think the parcel is worth.

"Mr. Whitmore made a good trade," Dennis said. "That land is in a prime downtown business area." Cable TV Still Uncertain for Loudoun

A New Jersey cable television company with offices in Winchester is one of several cable companies that have been wooing western Loudoun towns since April, when the jurisdictions of Round Hill, Hamilton and Purcellville dissolved their cable committee in a dispute over sharing the cost of a consulting fee.

According to Purcellville Mayor Ron Masters, the town declined to share the $16,000 fee proposed by Leesburg consultant John Niccols because the town was putting a great deal of its budget into a water treatment plant it is building with a $700,000 state grant. A representative from Clover Cable may make a presentation to the three town councils this month, officials said.

"People would like to have cable here," said Round Hill Mayor Jeff Wolford, "but they're not clamoring for it." When the Purcellville Town Council decided not to pay its share of the consulting fee, Hamilton cable committee representative Stillson Greene resigned, calling the vote "a death knell" to cable television in western Loudoun. Said Masters, "I'm not so sure any more that cable TV is the wave of the future. Our family got a VCR (video cassette recorder) for Christmas and I think these things will put cable right out of business." Leesylvania Park Project Over Budget

Estimates of potential costs of the Leesylvania State Park near Dumfries, dedicated last year and originally slated to open this summer, are seriously over budget and the park may not be completed for another decade, state park officials said.

According to park financial records, Phase I of the 500-acre park will cost $725,000 more than originally estimated and is nine months behind schedule. The cost overruns are projected for a 2.7 mile access road, expected to accommodate 2,000 automobiles daily. Cost for the road is estimated at $1.2 million. Construction is expected to begin this month, officials said. Because of the financial problems, a motorboat and sailboat launch originally planned as separate facilities may be combined.

Dumfries supervisor Ed King, elected Prince William board chairman last week, recently appointed Jerry Gardziel, a Potomac High School baseball coach, to the park authority board. Gardziel has lived in Prince William County and has taught in county schools nearly 20 years. Gardziel's wife Brenda is a Neabsco elementary school teacher.

The Dumfries Town Council held a public hearing last week on whether the zoning ordinance should be amended to allow the owner of a proposed mail distribution center to hire 20 people. According to zoning administrator Joseph Lamont, the current ordinance allows no more than 10 persons to be employed in any one area zoned for business. The privately owned center is slated for completion this summer, Lamont said. Quantico Drafts Taxi Ordinance

A three-man committee composed of the Quantico police chief, the town attorney and a council member is drafting an ordinance that will bring the town's taxi code in line with that of Prince William and surrounding jurisdictions.

The goal of the changes, according to Mayor Lively Abel, is to give the town more control over vehicle maintenance and persons employed as drivers. Officials on the Quantico Marine Base, which surrounds the town, are also updating the taxi code for the base, Abel said. Haymarket Seeks Police Officer

Haymarket's search for a police officer, begun when the town's only police officer resigned in October, is being hampered by a lack of response to reference checks.

According to Mayor Gertrude Bean, nine applications were received and are being checked, but so far officials have had only one response to reference requests. The town had hoped to have a new officer on the beat by Jan. 1. Although county police are picking up the slack, Bean said, Haymarket must have an officer in order to keep its town charter. Pr. William Reviews AIDS Policy

The Prince William County School Board last week reviewed new staff regulations on how to deal with students diagnosed as having AIDS. The policy follows regulations recently recommended by the Centers for Disease Control in Atlanta, according to school spokesman Kristy Larson. A team of health personnel will decide policy on a case-by-case basis, Larson said. School Library Gets Computers

The library in the Seneca Ridge Middle School in Sterling is the first in Northern Virginia to install computers and it is one of the few in the state to be so modernized, according to school spokeswoman Molly Converse.

The new IBM-PC allows the student to check out a book with the use of an optical penlight that scans the book card and the student's ID card in seconds, an operation that can sometimes take up to five minutes, she said. Other advantages of the new system include improved record keeping, easier sharing of resources with other schools and a faster rendering of overdue notices.

Said Converse, "the computer allows the librarian to send out 72 overdue notices in 10 minutes: That's a job that could take up to three days given all of the other duties a librarian has." By next spring computers will be in the libraries of Loudoun's other three middle schools and will be able to hold 50,000 titles. The school administration expects to ask for computers to go into the county's four high school libraries in the 1986-87 school budget. They would cost $5,500 apiece and hold more than 55,000 titles of books. Commenting on the new system, Converse noted that "librarians are coming to Loudoun from other districts just to see how it works."