tips # 2, 3 and 4

Tip #2: Don't be afraid to ask questions

If you're wondering about something, don't be afraid to ask Google. So far, they've always responded to my questions within a working day. There are two email addresses to use, depending on the type of question:

Please feel free to email us at adsense-tech@google.com if you have additional technical questions or concerns. For general program or account questions, please email adsense-support@google.com.

Their responses are always very polite, and they appreciate getting problem reports and suggestions.

Tip #3: Avoid non-English characters on English pages

This one is a bug, to be honest. My surname is French, and I prefer to write it out correctly with the accent grave on the first "e". Every page on my site would then include at least two accented letters, because my name shows up twice in the footer. On some pages my name shows up two or three more times.

Normally, this wouldn't be an issue. But on some pages the presence of the accented characters is enough to cause AdSense to display non-relevant ads in French. This happens whether the browser indicates a preference for French or not. When I reported this to Google, this is the answer they gave me:

Hello Eric, Thank you for bringing this issue to our attention. We are currently working as quickly as we can to address this problem. As soon as we have more information for you, we will email you again. We appreciate your patience. Sincerely, The Google Team

Until this is resolved, I've decided to strip out all accents except on the pages that are actually in French.

Tip #4: Check your keyword density

Although Google doesn't release exact details as to how they determine the ads to serve on a given page, they do tell us that it's the text content of the page that matters, not the meta tags. Before serving ads on a page, then, you might want to check its keyword density. A good, free tool for doing this is found here:

http://www.ranks.nl/tools/spider.html

This lets you fine-tune the page before exposing it to the AdSense crawler.

Basic Intro to AdSense (for beginners)
Adsense Earns
Adsense Alternatives
Adsense Blogs Hubs and Helps