Hi tdesws,
Sounds like a fun project! The first thing you need to know about making a game for the n900/maemo, is that it's different to your normal PC in a couple notable ways:

1. It's based on Linux, rather than Windows. Which means you'll want to lean towards Linux-style development. This also means you have a very powerful system, and have a lot of choice.

2. It's based on ARM rather than x86. This is talking about the sort of instructions the CPU uses. When making your own program from source, it's very likely going to be abstracted to the point that you don't even notice! However, it will be an issue if you try "move" a program from your PC to your N900 without recompiling it.

But the big thing is, that it's a very powerful environment that lets you do things your way. So if you're familiar with something like C or Python or C++ -- I'd recommend to just stick with that, and focus on your game!

Depending on your skills / ambitions -- I'd highly recommend having a look at Qt (and awesome toolkit written in C++). You can develop your game on what ever system you're using, and then later easily port it to your phone, or even another desktop operating system!

Good luck! The key is going to be persistance and taking small steps. Just do one small thing at a time even if you're not sure what you're going to do down the line, and if you have enough persistance you'll learn a lot and have something great.