You can't build an array without wrapping your head around how it works/looks
Think 3 dimensional.
plantation-productions.com/Webster/www.artofasm.com/Linux/HTML/Arraysa2.html
And when you understand, then its a lot of work and lots of testing to ensure that correct data is being stored, retrieved etc
It doesn't always work out as you planned and requires a lot of trial and error. I've been busy for the last month on data storage and retrieval. Some data needs to be randomized, some needs to checked against multiple criteria, no duplicates etc etc etc and I have not even halfway done.
Inventory systems are easy - wait till you have your hero accoplish tasks and check that those task are done in order to unlock/lock other tasks - lol.
I haven't made a rpg, but what I've heard it is one of the hardest games to make - lol, don't worry, they say it's also one of the most rewarding.
Check out C-7's game - scirra.com/forum/courier-play-now_topic62387.html
For inspiration <img src="smileys/smiley2.gif" border="0" align="middle" /> Motivation <img src="smileys/smiley32.gif" border="0" align="middle" /> And help keep you see bigger picture <img src="smileys/smiley10.gif" border="0" align="middle" />