Computers GOP: Computers at Washington national headquarters will be tied to candidates' headquarters around the country for the first time. ''Extensive opposition research program'' collects and stores voting and financial records of Democrats. Democrats: Trying to catch up in high-tech race. First two computer terminals should be delivered to Washington office this week. Have made computerized lists of voting records of Republican candidates. Fund raising GOP: Extensive mailing lists produced $37 million in contributions in 1981. Democrats: Expect to raise $8 million for candidates. Just getting going on fund-raising letters -- all income so far being plowed back into enlarging the effort. Political action committees GOP: Sending out emissaries to talk with conservative PACs that may support Republican candidates. Democrats: Playing catch up. Sponsored a forum on PACs in Washington. Candidate recruitment and assistance GOP: Nine field directors searching out top Republican candidates for House. Free training workshops for new candidates and their campaign directors. Democrats: Program in early stages. A training director and two assistants man phones in Washington.