So long as you follow the TOS, it shouldn't be any problem having Adsense...if you look around...there are many sites already having Adsense on their blog.
I have added Adsense to my Blogger blog. Maybe its more obvious on Blogger as its owned by Google! You can change the frequency of your ads and where they appear very easily. The facility doesn't appear to be as obvious on Wordpress although it could be a case of copying the code to a widget. I know there are lots of great plugins for Wordpress so it may help to check th plugin options.