It might be worth mentioning that prior to the changes last year, OU modules were really popular because they were quite heavily subsidised.
Now they are on the same fee structure as most universities, which means you can apply for a student loan to fund them, but you will use some of the funding you are entitled too. Most people are limited to a certain amount of funding, so it's worth checking before you choose - a lot of people this year have been caught out by this.
you don't necessarily need GCSEs/ A levels but you will need some kind of course that shows you can cope with academic study. For mature students experience does count towards your application but they do want to see some recent qualifications too - good luck