Not to be unfriendly, but all of these questions could be answered with very little research on your part. Part of building a project like this is learning these things, and if you can't be bothered with learning what a potentiometer is or what an encoder is, then maybe this isn't the project for you. The people here are a great resource if you run into real problems, but you shouldn't be asking them if a potentiometer and an encoder are the same thing. It comes across as lazy, and as though you think your time is much more valuable than theirs. Get on Wikipedia at the very least. Again, I'm really not trying to be unfriendly, but people new to electronics sometimes think that it's all extremely complicated and difficult to learn about, and it's not. While it's easier to just ask others to do all the work for you, you don't really learn anything that way, and the fact is that it's extremely easy to find this info. While PICs and SIDs aren't used in every electronic device in your house, the rest of the parts and concepts are, so don't think that you need to learn all that stuff here. Look around. Also, any problems you run into have probably already happened to someone else, so search these forums before you ask, and you may just find a ten-page detailed solution to it. Good luck!