I second what TsaranfProphet said. I'll only add that if you can, find a book that comes with answer keys for the exercises. Not all of them do. Having an answer key makes a huge difference for self study. It also helps quite a bit to have someone who's proficient in the language you will be studying, whether a faculty, a grad student, a friend, etc. so that if you get stuck on anything and the textbook/answer key provide no insight, you have someone to turn to. Answer keys are invaluable, but there are limits to what they are suitable for.