I LOVE homemade salsa. It's pretty good canned as well, but nothing beats fresh salsa and tortilla chips. Mmm... my mouth is salivating right now. Seriously, this is the best.
So there isn't really an amount to anything here, just make as much as you want. But when I make it, I make alot. So I'll give you what I usually do.
3/4 green pepper, chopped
1 lime, squeezed
1 chopped jalepeno (remember the seeds inside are what is really hot, so don't just chop the whole thing and put it in unless you like it REALLY hot... I'm telling you this from experience. Although, that batch did last a long time, because we couldn't put very much on each chip!)
1/2 onion, chopped
cilantro - optional
I cut the tomatoes first, and see how much I have, then add a small amount of everything and keep adding what I want until it tastes just right. But those amounts are generally what I end up using. Sorry, this is kind of generic but it gives you the opportunity to make your best salsa, just how you like it!