I'm thinking of using Java to write a program that I might try to sell one day. I'm new to Java so I have to ask, what types of tools/software/etc will I need (from development, to distribution, to user-friendly installation on users' machines) that have licenses that must be considered to make sure they allow sales and closed source code, etc.?
Should we assume the user already runs at least one Java app, and therefore has a fairly recent version of Java on their machine?
Also, do you have any recommendations for specific tools that are definitely suitable for this purpose?
It's very rare to see any development tools that restrict the way you can use software created using them. The only exception to that are libraries, and that is not a problem with standard Java libraries. Tools, IDE and so on - regardless of whether they're free or not - will not affect how you can distribute your code.
There are some weird exceptions, like BitKeeper source control software, the license of which prohibits anyone using it from trying to create software that could compete with BitKeeper - which is why I advise to stay as far away from the thing, and the company behind it, as possible. In the end, if you want to be absolutely legally clear, you'll have to hire a lawyer and have him go through licenses and EULAs for all software you're going to use in your development process, because of stuff like this.
Some specific data points: Java itself is okay (both compiler and libraries); both Ant and Maven are okay; and Eclipse and NetBeans are okay.