First, welcome to Prolog! I think you'll find it rewarding and enjoyable.
The books I routinely see recommended are The Art of Prolog, Programming Prolog and Clause and Effect. I have Art and Programming and they're both fine books; Art is certainly more encyclopedic and Programming is more linear. I consult Art and Craft a lot lately, and some weirder ones (Logic Grammars for example). I'm hoping to buy Prolog Programming in Depth next. I don't think there are a lot of bad Prolog books out there one should try to avoid. I would probably save Craft and Practice for later though.
You can load multiple files at once by listing them:
:- [file1, file2, file3].
ALso, since 'name.pl' ends in '.pl' you can omit the quotes; single quotes are really only necessary if Prolog wouldn't take the enclosed to be an atom ordinarily.
Hope this helps and good luck on your journey. :)