i would advise wordpress.org also but you need to install it which is where i've hit a brick wall because i have a mac. the only alternative i see is to find a host that has Fantastico, then installation isn't a problem.
i recently violated a Term Of Service at wordpress.com which is a free blog service. i was told afterwards that i was allow one discrete link. basically as i understand wordpress.com is a free search blog that doesn't allow any commercial promotions.
wordpress.org is an installation software.
for all the headache i've turned to typepad.com, which isn't as good, but it's a one stop solution.
any and many web-host will offer a blog service but in my opinion it's a matter of trying these things out. you can always move your blog if you're not satisfied.