HELP me get my new Craftsman bandsaw model 124.3299 working right!

I got this Craftsman bandsaw model 123.3299 from Ace Hardware. I looked at it for years and knew I wanted it. But, I've tried everything I can find about how to do the setup and I still can't get cuts that are square. The blade always twists no matter how much tension I put on it. I've used the dollar bill method of setting the blade guides and still don't know what I'm doing wrong. Also, this saw is on the lowest speed and I think I want to change that to the highest speed because I think I will be cutting thin aluminum barstock - I will get the fine tooth blade which Ace has in the store, but first I need to know what I don't know! What is it that is not in the manual that I haven't found anywhere online yet? One of you will get me onto the correct pathway to bandsaw success! I know that probably a bunch of you know what to do.... so hook me up with the best bandsaw advice you have....