Chris
This is something that I have struggled with for a while - I setup the site a few years back to try and help me decide but I just got sidetracked with learning about the web and didn't put as much work into the site as it deserved (until now!)
One thing I've found about the internet is that there is a website about absolutely anything and that these websites use programs such as Adsense or CJ.com (amongst others) to monetise their sites.
The best way forward probably is to pick a hobby or interest of yours and do a bit of research about it - see what other sites offer and how they make money from their site - checkout sites like Digitalpoint.com and Sitepoint.com for great ideas about making money from websites.
One of our members on the portal site posted an article about how he makes money from having a poker blog (weblog/online diary) - the article is here
http://www.wfhn.co.uk/The_News/Business_Opportunities/Making_money_from_Poker_without_Gambling!/
It might be a good read and provide some insight into how a simple hobby can generate some much needed cash.
Lyndon