In FO: New Vegas I usually collect all skill books. Here in Fallout 3 there seem to be a lot more skill books than in FO: New Vegas though. Does it take considerably longer to collect them all?

Do you collect all skill books?

There's 23 Barter books, I think there's about 25 each fo every other skill book. Though for some of them it will depend on a quest/perk choice or purchase of some of the house themes. I got all the books I could get as a very high karma character who's not above stealing.

Also have all 101 pre-war books, music sheet books (traded one for Blackhawk), Danielle's book, pre-war junk version books, Paradise Lost (unique Lying book), Lincoln's diary and the Krivbeknih.

Edit: forgot the Wasteland survival guides. Also, you can get unlimited Science and Explosives books.

It seems like you could almost start with 1 Int, or maybe 3 Int for Comprehension, and still max out almost every skill by collecting all skill books.

Probably. I maxed out a number of skills and all my SPECIAL points are at 10 even without using a single skill book. Though having an intelligence that low might give you some trouble during quests.