See advice on "Novice" thread.
Right here, right now, what you want is a 'Mentor'; who should have decent marked maps.
An OS or two, will just encourage you to go out exploring, possibly where you shouldn't, on trails that are NOT 'Status Confirmed'
If you want the quick and easy route to 'marked maps', (and every-one does!) join GLASS, and/or local Landy club, and talk to the Rights of Way secretery.
They'll tell you which OS maps to get, and will arrange a 'mark-up' session, to copy routes accross from thier maps to yours, and tell you the CURRENT status of each one.... but you have to be advised, status's change, and you need to keep re-checking them.
For Now, dont try diving in too deep; go with the Mentor idea, and work to thier maps.
When you have done some trails WITH your mentor and got those routes on your own maps, you can have a crack at driving routes you have driven WITH them, over again, with your buddy, becouse you should know what to expect on lanes you've already driven.
When you have a fair bit of experience on the trails and encountered a fair range of conditions and situations, THEN, you might like to try driving some trails 'blind' without your mentor, but get THEM to advise you which trails they think you could reasonably tackle, dont just go off trying trails on spec, or you are bound to get into trouble at some point!
