Agreed, the maths is the thing that you definately need to get to grips with, as it will run through all of the subjects.
Make sure that you do the higher maths within the course, as there was the option of not doing it, but if you plan to go onto do a degree, then you will need this.
Get yourself a good scientific calculator, and learn how to use it back to front. I still have my calculator from when I did my HNC, and it lived with me through my degree and I still use it today, 20 years on!
Yep, get some good books, and they should give you a reading list. Also, if the college has a library, make sure you get a library card straight away, and get straight in there and get the books out of the library. Saves a few quid.
Other than the maths, one of the hardest things is getting back into the swing of studying. Be determined, and make sure you do lots of reading and independent studying outside of the time you are in the classroom.
From memory, you have five subjects a year, and an exam per subject per term... therefore, 15 written exams per year. So there is a fair amount of work to get through.
Good luck, and use the forum.
Yooj