I am fairly new to cooking ROMS myself. I have not publicly posted any of mine because of how noobish they are. However, when I was younger I dabbled in
VB, C++, HTML, Java and a few other languages. However, I feel that just simply reading and soaking in as much as possible is the best way to learn. Between this site and Xda, there is SO much you can learn from the posts alone. Once you start getting into it, getting that fear outta your mind and just going for it you will realize its not as scarya as you might think. These devices are amazing and the possibilities are almost limitless. Just dont be afraid to get yer hands in there!
lol
I dont think previous programming knowledge is mandatory. Having that backround sure is nice, but I dont think required.
good luck!