Last year, Debbie Reynolds was just getting ready to release a follow-up to her successful "Do It Debbie's Way" exercise tape (130,000 copies sold) when the video company folded. Now, "Do It" is being rereleased by another firm, VidAmerica, on Aug. 11, at $39.98. VidAmerica "contemplates future productions" with the star. Information: (212) 355-1600. . . . Isaac Asimov is the host of "Voyage to the Outer Planets and Beyond," a new Today Home Entertainment video featuring NASA and JPL footage from the Voyager Space Mission and a classical-music sound track. Information: (213) 278-6490. . . . Has watching videos cut into your reading? Ease your way back into print with "Fast Forward: Hollywood, the Japanese and the Onslaught of the VCR" by James Lardner, published by W.W. Norton, an account of the movies-versus-tape conflict that led to a Supreme Court decision assuring the legality of normal video home-recording. . . . Or has the VCR kept you from fixing that leaky faucet? Try "Reader's Digest Videomanual of Home Repair," a 110-minute tape from Random House. Information: (212) 872-8036.