Sorry for the late reply. To be honest I've never done much practice mapping, I would want to help you but I'm not a good choice as I am right now, sorry man. :P
Thanks. Yeah, I was going to start with a GBA game, looks like they have the most tutorials and tools to use. I remember using Advancemap w/FSF and some scripting program a few years ago and that was cool. Gonna see what's available.
Pleased to meet you sir. If you are intrested in ROM hacking then you should go to that section and search for tools/tutorials. I would say to hack FireRed US 1.0. Cuz it is the easiest. Have a nice day sir. Thanks.