This book is by Tom Downs and is the one my teenager swears by (though I have asked him to cut down on the swearing). It is published as Gene says by Bicycling Magazine and is something of a classic "Bible" of bike repair. Me, I gave up on bike repair years ago, figuring I didn't have the necessary cortical elements, so I just take my bike once or twice a year to the bike shop! (example, in a failed attempt to raise my steering wheel I accidentally loosened my steering wheel so it would be much more responsive to turns - I really like it like this, but as I say, it was an accident and I don't know if it will kill me. If I should die of this, I obviously can't report it here)
Gene Tenner said:
Bicycling Magazine's Complete Guide to Bicycle Maintenance and Repair
My copy is 20 years old and I still use it, even though technology has changed considerably. It covers all the basics in simple language with photos. The link is to Amazon, but I am sure you can get copies anywhere online.