I knew pretty much nothing about auto electrics when I began ........ was really afraid of destroying my van while attempting it.
As Mr Gazm says, there's a lot of research to do, but then how do you know which install 'howto' to follow, some are a little iffy as I found out at a later date, once I became a little more knowledgeable on the subject.
The following link should help out a little. At least it will show you the basics of a good setup. They also sell ready made 'kit's you just wiring them in. I would say, go for the best you can afford, like the heavy duty type. You will learn in time that you're forever adding extra luxuries and gizmo's, so an expandable system that can cope with heavy current requirements will pay off in the end.
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http://www.xtremevan.co.uk/product_info.php?products_id=5026
You can of course design and fit the entire system yourself, you need to know a lot more to do it that way, as you will need to determine what is a good quality product as opposed to Chinese garbage.
If you're not sure of your auto electrical work, you can always run all the cabling, install the leisure battery, do various connections ..... then take it to a qualified auto electrician to complete the install and test it for safety.
Hope that helps mate.
TURK