If you use Wordpress.com, here is a link explaining the above (no adsense):
AdSense and other Ads « WordPress.com
I would recommend using Wordpress.
org. You host this on your own site and can find many templates to use Adsense in your blog. For hosting check here:
http://wordpress.org/hosting/.
I personally use DreamHost (listed on the above .org link) and LOVE, LOVE, LOVE it. It truly is one button installation. I had my blog up and going in no time. If you link through the above link, WP.org receives an affiliate payment (I think) and you get a 20% discount on your first payment whether you choose monthly or one of the other lump sum payments. I think you get a free domain name with it, but I don't know, I didn't need it.
Obviously, this costs money upfront for the hosting, but you have full control over your site. It is also a much more professional image for your own domain name compared to a sub-domain name. A definite plus.
