OP, if you're simply looking to be able to create authority sites, and manage/edit them on your own, then my suggestions would be as follows. Firstly, you'll need to learn HTML along with CSS - FULLY! Once you've got a solid ground in those both, then start watching some PSD to Wordpress tutorials to get yourself accustomed to the designing/coding process behind creating a website. Furthermore, after becoming an efficient designer/coder (it would be in your best interest to learn about design theory or User Experience design, to insure your sites have maximum appeal to your users) I would suggest you jump right into either PHP or Javascript (of course learning it FULLY via tutsplus or codeacademy etc.), have a basic understanding, and only then should you start dabbling on your own IM projects.
I myself was in your same situation, and actually put IM to the side for a good 7-8 months in order to gain a strong grasp on Web Development; it's not a simple process after all.
Now..I'm not sure what it is you plan on doing on the software side, but you won't need to learn Java/C or any other software language, for your authority site.
Hope the best!