The first link posted by SaabDastard indded looks comprehensive.
Here's another that also includes a link to MBAM, which is along similar lines to AdAware but several cuts above.
Superantispyware is another similar scanner well worth installing. These 2 scanners are genuinely free and remove what they find. Usually very well.
Just out of interest, what AV and Firewall do you use?
A popup blocker and setting scripts to "prompt" may be useful. This can be done in IE, but is somewhat more straightforward in FF by the use of add-ons. IE7 is (or can be) as secure a browser as most of 'em. FF has the reputation of being more secure, but I think these days differences are detail and statistical. (More IE users = more infections.)