Armed with the names of 25 persons, including three women and at least one black, Sen. John W. Warner (R-Va.) began a tour of Virginia yesterday in search of nominees for three federal judgeships.

As a member of the new majority Republican party in the Senate, Warner said he will be "sitting as a one-man selection board," although he pledged he will follow guidelines of the American Bar Association in suggesting nominees.

Warner began his tour in Alexandria, where a vacancy has existed for two years. He met with U.S. District Court Judge Albert V. Bryan Jr., who urged Warner to speed up the selection process. Warner said he plans to offer the names of three to five candidates for each vacancy by June 1.

"I am making a personal effort to ensure that women and minorities get full consideration for the vacancies," Warner said. "The persons selected for the vacancies will be chosen on merit and quality, not by political considerations."

Although he would not identify anyone under consideration, Warner said he would be interviewing one of the women today in Richmond. He will go to Norfolk on Wednesday, Abingdon and Roanoke on Thursday and Charlottesville on Friday.

He also will meet today with Richmond Circuit Court Judge James E. Sheffield, a black whose nomination during the Carter administration was withdrawn after a conflict of interest allegation was raised. Warner said Sheffield has told him that "he is not interested in getting involved again."