true, the white paprer is a bit intensive for any non-geek, but OP should at least have a look at this thread
https://bitcointalksearch.org/topic/new-to-bitcoin-start-here-7269 before blindly wandering in. there is a lot to get familiar with.
also, OP, experiment with various wallets using very small transactions... they say that is what faucets are good for... getting small amounts of btc to experiment with.
as for using multiples of the same wallet client on the same machine... you don't need to, or at least i dont know why you would want to... for example... if you have one multibit client, you can create new wallets within it (look at the left panel on the UI)
I think you can have multiple online wallets from the same provider... I've never bothered to try it, dont use online wallets much, they arent secure. but if you must, i would suppose you could make multiple accounts with multiple emails and usernames.
it just sounds like a recipie for disaster though. If you cant hardly understand how to use btc in the first place why do you want to multiply that by piling up many wallets? Keep it simple, learn the ropes... then go nuts.
thats just my advice. good luck.