Good for you Kerri!
I can speak from my own perspective of going back to school very recently, after 20 years and I'm a university student advisor - I have experience on both sides of the pond.
First thing I would do is look at programs and see what they're all about. You might be able to narrow down your program just from the courses. There are so many choices but you can most likely narrow them down from proximity to your home and what your interests are.
Once you find a few that look promising, then contact the schools. You will be entering as a mature student so there will be different entrance requirements for you than for an A-lev or transfer student. Start with admissions and see what feel you get. They will also clarify the entrance requirements for you in your program of choice. I would highly, highly advise speaking to an advisor in your faculty of choice; someone who can speak specifically about the requirements of the degree programme.
And finally, once you have all of that information, then worry about what you have to do to get there, with transcripts etc..
I know from my own experience of going back to school, that it has been fabulous and I love being a student. I just wish I didn't have to work full-time as well, in order to pay those pesky bills!
Please pm me if you want; I'm happy to help.