Your best bet (starting out) is to code your game and name your rom files the same as an existing game like Puzzle de Pon. Then you can just load your game into MAME, ignoring all the crc mismatch warnings.
Second to that, you can modify mame source to add your own driver. You can read more about the mame source on mame's site (
www.mamedev.com) and download the build tools.
If that sounds like too much work, try and locate NeoRageX. This will load just about any .zip if it finds the necessary files it needs to run a game.
You could also try Nebula. It uses an external driver file. You can download the driver files from my site with my simple demos (
www.neobitz.com) to see what is involved.
As for building a cart -- that's not so tough either. Just pick up a cheap cart and yank the mask roms and replace with low-profile sockets. Then burn eproms and try it out. Sure, there's a little more to it than that, but if you put your game onto same size eproms as the mask roms from your host cart, that's 90% of your battle.
Nobody (as far as I know) has really created a faq for this sort of thing.
Jeff