I'll second the recommendation of Gentoo. I used to be a Red Hat guy, but Red Hat is slowly bleeding out functionality with each new release. The Fedora Project is the biggest crock since the Meech Lake accord. I like Red Hat 8 still, even though I have to download a patch if I want to play mp3s in XMMS.

Slackware will be an easier install, but it's a nightmare to add software to. People complain about RPM, but Slackware's .tgz packages are even more useless. You'll wind up downloading source and compiling it yourself more often than not.

Gentoo will be a nightmare to install, but it's short term pain for long term gain.

However (especially if you're going to use Gentoo), I reccomend that you not only read but *study* the installation instructions. Especially if you're using an ATA card instead of one of the IDE channels on your motherboard. And even more, I'd reccomend installing Windows and Linux on separate physical disks. (Windows on hda and Linux on hdb). Plus, you'll have to learn both GRUB's method of naming hard drives and partitions and Gentoo's, which IIRC, is really confusing. Still, if I can learn ARC paths, you can learn Gentoo's system.

Re: Programming: I have used KDevelop, and it's crap, especially put next to Visual Studio. Anjunta's better, but still not as good as Visual C++.