I just recently got my first mac. I do lots of programming on windows but now I want to get into Mac development. What are some languages i should know or tools i should use to
For desktop apps, cocoa+objective-c are the way to go. XCode is the best editor for that. For webapps, I'd check out Ruby on Rails and Textmate.
If you've done Java development, you can keep on doing that, too. Eclipse will be very familiar.