I agree that more tutorials wouldn't hurt. I think the solution for this is to improve the Maemo wiki and advertise it more.

I would recommend going through the wiki for topics that interest you. If the wiki doesn't contain what you're looking for, ask (this forum, mailing lists, irc). Maybe someone will write a wiki page about the topic in addition to answering your questions.

If you're interested in shell scripting I suggest looking at the Linux documentation project's Bash guide for beginners. Please note that Maemo is not using bash, but the basics are mostly the same. For available build-in commands in xterm type help.

If you want to write applications for Maemo I'd suggest looking into python or Qt.

You only learn by doing