A governor, lieutenant governor, attorney general, 100 state legislators and numerous local officials will be elected today in what has been called the most costly and one of the most bitter elections in Virginia history.

Polls open at 6 a.m. and close at 7 p.m.

For only the third time this century Virginia voters will be asked to approve sale of general obligation bonds to finance state construction projects. If approved, the $125 million in bonds would be the second bonds Virginia has issued since the state abandoned pay-as-you-go financing in 1968.

In teh race for governor, Democrat Henry E. Howell, 57, a Norfolk lawyer and former lieutenant governor, is waging his third race for the office that eluded him in 1969 and 1973. The present lieutenant governor, Republican John D. Dalton, 46, a Radford lawyer, is his major opponent.

Alan R. Ogden, 31, a Richmond resident and a member of the Virginia Labor Party, also is on the ballot for governor, running as an independent.

The current governor, Republican Mills E. Godwin, is ineligible to succeed himself under Virginia law. His successor will serve a four-year term and be paid $60,000 a year.

In the race for the part-time, largely ceremonial office at lieutenant governor, Democrat Charles S. (Chuck) Robb, 38, of McLean faces Republican A. Joseph Canada, 38, a state senator from Virginia Beach.

Another Republican state senator, J. Marshall Coleman, 35, from Staunton, faces Edard E. Lane, 53, a Democratic state delegate from Richmond, in the race for state attorney general.

All 100 seats in the State House of Delegates are up for two-year terms, including 40 candidates who are seeking the 19 House of Delegates seats from Northern Virginia. Most attention in the legislative races has fo- cused on the efforts of House Majority Leader James M. Thomson, 53, to retain his Alexandria seat. A Democrat and member of the house since 1968, Thomson is involved in a three-way race with Del. Richard R.G. Hobson (D-Alexandria) and Republican Gary Myers, 33, an Old Town lawyer, for two seats.

Currently 14 of the Northern Virginia house seats are held by Democrats and the remainder by Republicans. Five of the House incumbents - three Democrats and two Republicans - are not seeking re-election.

In Arlington, voters will select a new member of the County Board from three independents - incumbent Ellen M. Bozman, Sherman W. Pratt, and Arthur C. Vogel - name a new county court clerk and decide the fate of $15.2 million in proposed bond issue.

Loudoun County voters will be asked to approve $2 million in building project bonds and Alexandria voters will elect a new sheriff. Local officials also will be named in Falls Church, Fairfax City, Manassas, and Manassas Park.