If you don't mind me asking, how long have you been out of school? That may affect the transition in some ways because someone who has only been out of school for a couple of years may have an easier time going back opposed to someone who has been out for many years. It also depends on the person.
The best advice I could give would be to do a lot of research before diving into anything. Research possible colleges and go visit them to gain more information. It's one thing to get a brochure on a college and make a decision that way and another to actually go visit the places. You will often get a lot more information and a better feel for the college’s community and campus life. If you’ve been out of school for awhile, this may be a way to get reconnected with being on a campus (if you’ve been on one before) or learn general information about being on campus (if you’ve not gone to college previously).
For the psychological aspect, again, information is key. You really have to know yourself and know if it something that you really want to do because if it’s not, it’s just a waste of time when you could be doing something different with your time. I know some people have an adverse look on counseling, but it really does help and it really can help in this situation so that you can learn more about yourself and what you’re capable of. If you’ve been out of school for a while, this may greatly help with deciding what program you want to major in--especially if you don’t already know--and it’s a great way to get to know yourself a better in general.
Either way, I think I’ve gone a bit more of a ramble than I really meant to, but gather information is very important and really knowing yourself (your stress limits, your determination, your time management skills, etc. because all this is good to know beforehand) is another important aspect. But yeah, that’s all I got with the basic information you provided.
Three years (rounding up) isn't that much of a gap, so things probably haven't changed much from when you were attending before. I would still go visit campuses and get a better feel for things and gather as much information as possible before making your final decision.
Just reading up about the college and its services helps me but everyone is diffrent. It shouldnt be too bad going back after bieng out for a short time but if you think you might have some problems maybe you should think about doing a semester part time or only take a couple classes at first, you know, just to get the feel of things again.