Kate or Bluefish are both good for Linux, I prefer Kate since I had some issues with Bluefish's syntax highlighting failing.
I would recommend using something basic like one of these which wont help with your code to start with, then you'll actually learn it rather than rely on the program to do it for you.
I'd go for Aptana. Although I've been trying NetBeans recently. I like this too. Both available for Linux and Windows.