WHAT YOU'LL BE SEEING DURING CONVENTION WEEK

Monday - 20th The convention gets under way with the report of the credentials committee, a routine task. Unlike the Democratic convention, there are no Gary Harts or Jesse Jacksons to complain about not receiving enough delegates after winning sizeable shares of the popular vote in the primary battle.

* Party chairman Frank Fahrenkopf will preside over the evening session.

* Prime-time events: brief speeches by Sen. Howard Baker of Tennessee, majority leader of the Senate and a likely candidate for the GOP presidential nomination in 1988, and Rep. Guy Vander Jagt of Michigan, another presidential prospect.

* Preceding and quite likely upstaging the keynote address by US Treasurer Katherine D. Ortega: United Nations Ambassador Jeane Kirkpatrick, with what party leaders expect to be a strong speech on foreign policy.

* Miss Ortega, says a campaign official, ''is very genuine, and that sincerity comes across.''

* The keynote speech is scheduled for 12 minutes.

Tuesday - 21st

Reports of the credentials, rules, and platform committees will be heard and voted upon. No floor fights are anticipated, say campaign officials.

* GOP ''stars'' scheduled to appear on the podium Tuesday evening include Rep. Jack Kemp of New York and Sen. Richard Lugar of Indiana.

* Former President Gerald Ford also will speak.

* The evening will end with ''back to back'' speeches by Sen. Robert Dole of Kansas and his wife, US Transportation Secretary Elizabeth Dole - a lively tandem designed to lend a bit of spark to the convention.

* The appearances by members of the ''Class of 1988'' will give American TV viewers a look at the future GOP potential.

Wednesday - 22nd

Nominations night will open with tributes to Sen. Barry Goldwater of Arizona and First Lady Nancy Reagan.

* Sen. Paul Laxalt of Nevada will place Ronald Reagan's name in nomination.

* After the President is nominated for a second term, doubtless by acclamation, California Gov. George Deukmejian will nominate Vice-President George Bush.

* Reagan will have arrived in Dallas and will watch the convention proceedings from his suite at the Loews Anatole Hotel.

Thursday - 23rd

After Vice-President Bush's acceptance speech comes the culminating moment: the President's acceptance address.

* In a break with tradition, Reagan will be introduced by the showing of a 12 -minute documentary film, not by a speaker.

* Reaganites are eager to have the viewing public see the film, which will include scenes from the President's travels to China and other countries. TELEVISION COVERAGE.

Convention-coverage plans of the three major networks are not complete. CBS and NBC apparently will provide prime-time coverage of major events. ABC says it will cover ''the news of the convention.'' Gavel-to-gavel coverage will be available in most viewing areas via cable and on some public TV stations.