Collector's Guide Publishing Inc. is a small press based in Burlington, Ontario (my hometown!). The company started in 1984 by Robert Godwin to publish books on music artists (specifically Led Zeppelin). Since then, they've branched out to include the interests of Robert's brother Richard: Science. Under the imprints Apogee Books and Apogee Prime, they've published several books in conjunction with NASA about the various space missions (and include extra content with the books in the form of DVD-ROMs).
If that's not enough to interest you then maybe this will be. They've also started publishing reprints of out of print science fiction novels. So far they've only got a handful, but it's cool to see so some of these unknown classics come back into print.
Robert Godwin does afterwards for the books, explaining their significance to the field of science fiction.
Click here to see the full listing of their SF books. They've also got a helpful guide of independent bookstores where you can buy their books in several countries (and note, it's not listed, but the World's Biggest Bookstore in Toronto carries several of their titles).