when starting with final fantasy I suggest starting with the real one i started at, it wasn't Final Fantasy on the nes, it was final fantasy II (or IV on the ps1, gba) on the snes, man that was a fantastic game. I have played and beaten it more times than any game you have ever played and beaten! and just move on from there (although I wasn't a big fan of final fantasy V), VI was the bomb (known as 3 on the snes), VII was alright, but I like VII, IX and X WAY WAY more. X-2 was ungh... but peep kingdom hearts 1 and 2 after you are done with these, you will enjoy them so much more.
Seriously though start with IV/II (depending on what you planned on playing it on. you will not regret the wonderful stories you are about to endure!