Starting with Adsense...

I am writing this for those of you who already own a blog or website but have yet to see AdSense perform for you.

1. On Topic Content
If you have a blog about the iPod, then stick to writing about iPod news, iPod accessories, iTunes etc. There is no point writing about iPod and then starting to talk about your day at work within the same page. AdSense works through a contextual assessment of your page, so try and make it as easy as possible for the Mediabot to ascertain exactly what you are writing about.
2. Optimize Tags
Making Mediabot’s job as easy as possible also means optimizing your HTML tags, from your meta tags to your header tags. Place your target keywords in the page title, meta description and keywords tag, as well as in your header tags. Don’t forget to bold or italicize your target keywords throughout the content.
3. Ad Placement
Consult the AdSense heatmap and apply it to your layout. You’ll find that CTR will increase when you place your ads above the fold. Placing ads down the left (where users are used to seeing navigation) and in central locations will also increase CTR. Don’t forget to place ads at the bottom of a page for readers who have scrolled down to the bottom of a long article. I would not advise placing your ads down the left hand of a page as CTR in this location is normally quite low. So keep them above the fold and smack bang in front of their eyes.
4. Colours
The basic premise with regards colours is to match your ad colouring as closely to the colour scheme employed through out your site. I recommend using the same colours for text and links for optimum CTR.
5. Borders or No Borders?
Answer, no borders! Keep reminding yourself that your ads need to slot in with your existing layout and appear to be part of the page. A border immediately separates the ads and decreases CTR.
6. Images
There has been a lot of talk on the boards for quite some time about using images alongside ads to improve CTR. Overall, images placed beside your ads will increase CTR. Here’s a handy tool to generate the code you’ll need, courtesy of Shoemoney.
7. Section Targeting
Use the section targeting tags, they make it easy to specify what content Mediabot should spider and what to ignore.
8. Use Alternate Ads
On occasion AdSense will not be able to display any ads in an ad block on a particular page. Unless specified AdSense will display Public Service Ads (PSAs) that do not earn you anything. So when you are creating your code, specify an affiliate link or image linked to an affiliate product. Therefore you can rest assured that no matter what happens, you’re earning!
9. Use Channels
Track your performance by channel, a technique that is especially important when you have place multiple ad blocks per page. Assign each ad block a unique channel so that you can see what performs best over time, allowing you to further refine ad placement and increase revenue.