This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
That's a loaded question . I can't really say for sure, and it changes from week to week and project to project. That's what's great about plugins and OSS in general -- there are extensions that can help you with pretty much any task.
In general, I find the following to be applicable to just about every project and completely indispensable: