Hi Paul..
I see no one has replied to this yet.

I think it might be better in different location on the forum so I shall move it into the best spot.
As for how much you spend on adwords, I think a lot of partners spend anything between #5 - #200 a day. However the sky is the limit and people have been known to spend thousands!
With smaller numbers its a little more difficult to optimise your ads as you need to leave them runing longer before you can make decisions on what is working and what is not.
With the new tiered commission rolling out soon this will encourage people to spend more as it will make it more profitable, on a bigger volume which obviously equals bigger payouts!
I suggest you set yourself a monthly budget, use this to calculate how much to spend a day. Do some research on the theory of adwords by reading some ebooks. Build a list of keywords and a couple of campaigns.. and leave them running. It is important not to give up or stop as you will see better results after a month or so from the same ads.
Then when you start to see a profit put it back in and keep increasing your montly spend.
Hope this helped