I've also heard that Bruce Eckel's Thinking In Java which is also available online in an electronic format for free. Personally, I prefer hard copy, but you may want to browse the online version before commiting the money to buy it.
Of course, you can also visit Java Ranch to ask specific questions. There are a lot of people here than can help clarify the parts of the language that you don't understand.
Also, you should bookmark the API docsthat are appropriate for the version of the SDK that you use. This is an invaluable reference once you learn how to navigate it.
Originally posted by Ric Flair:
Hi! Can anyone recommend a beginner book? I have Head First but I'm having a little trouble with it. Is Ivor Horton's Beginning Java book ok? Anything better? I've seen so many conflicting reviews for newbie Java books and I'm now confused! Thanks in advance!
I've read Ivor's Beginning Java book a number of years ago when I transitioned from C/C++ to Java and found it a pretty good book. Of course I read already knowing basic programming and Object-Oriented concepts so you need to take my recommendation with that grain of salt applied. I've also read other positive reviews of it. I've also read some positive reviews and feedback about Thinking In Java that Layne suggested.
There are also some good, and free, online references. Take a look at my post (you'll need to scroll down a ways) in this thread. One or two are repeats of ones posted by others above, but there are some others listed there.