Rules to remember:
1/. Do not go alone ... EVER!!! Find someone with a bit of experience to accompany you
2/. Make sure that someone knows where you are, and what time to expect you back safe
3/. Take either flasks of hot drinks or a means of making them
4/. Take some energy food, as getting yourself unstuck is very draining on your body reserves
5/. Make sure that your vehicle mechanics and electrics are in top condition
6/. If you don't already have them, fit extended axle breathers
7/. Reduce your tyre pressures to around 16psi and take a pump with you to reinflate them afterwards
8/. Take a comprehensive tool kit, as you will probably need it
9/. Go along to some RTV Trials and see how others manage off road in road trim vehicles
10/. Have fun, and expect to break something!