I attended college during my last two years of high school. In my case, I didn't save any time in college--I took a lot of courses I wanted to take, like French, cello, and historical linguistics--but I got to explore lots of things that interested me, and I got lots of transfer credits, too. In my opinion, it was well worth it. I got a lot more out of those "extra" college courses than I ever got out of high school.
That said, whether or not the college credits are accepted by your university of choice depends on the university. Each school makes its own determination. If you're looking for guidance as to how to select courses now that will most likely transfer, you'll need to talk to an academic advisor at the university you plan to graduate from. He or she will know what his/her school's policy is.
In my experience, a university is first going to look at the formal course description of the class you took at your local community college/current school. If the course description closely matches its own description and has the same number of credit hours as the university's, then you might have a good shot of getting transfer credits. However, if there's a non-negligible difference between the course you took and the university's version of the course, the credits might not transfer.
One final piece of advice: Get all communication from the advisor in writing!
Anecdote:
I TA'ed some labs over the summer. One of my students who was taking my course shared with me why she was taking it: Her first advisor had told her (in person) at the beginning of the spring semester--which was supposed to be her final semester in college--that Course X that she had taken at another college would count towards her general science requirements and that she would graduate in May, as she had expected all along.
However, that advisor left the university that same semester. When the student went back to the advising office to do her "graduation check"--the process that verifies that the student satisfied all the requirements for graduation--she met with a different advisor who REFUSED to count Course X. Since the student didn't have the previous advisor's approval of the course in writing, the student had to take another science in the summer, paying full price for it--there's no financial aid, loans, or scholarships offered for summer school--delaying graduation AND getting a job.
Caveat emptor!