Hi Sadie,
There are lots of hints and tips on here, and I recommend that you take some time to read some of the threads, as a lot of the guys are very knowledgeable.
It really all comes down to personal preference, and availalbility, if you don't want to go down the route of 'specialist ' stuff ordered from the Net, which can come in quite expensive.
There are quite a few threads with links to chemicalguys and carwashnwax, these sites are worth a look if you want to folllow that route, also detailingworld will give you an idea of what can be acheived.
This can spiral out of control though and there are people on here who spend DAYS cleaning and washing their cars, (and it really shows....they look tremendous !!)
Personally I like Maguiars, which you can pick up in Halfords. It is a little more expensive that your average wax/polishes, but as with everything in life, you get what you pay for. You can see from my signature pic the sort of finish that you get with Maguiars.
I'm sure that some of the 'detailers' on here will be more than happy to give you advice.
Good Luck