Here is a quick tutorial showing you how to add an Adsense block to your blogger blog above the Post title. I have been asked this question frequently as I do this on my main Make Money blog. The reason for doing this is not so obvious - it really comes down to the fact that I have found much higher CTR (click thru rate) with the ads placed above the title rather than the more common position below the title.
The process involves adding "Add a Gadget" boxes to your existing template. Please see How to Add a Page Element (Gadget) to Blogger Header
Rather than re-hashing the steps just follow the instructions in the linked post. This will allow you to add the necessary boxes for adding gadgets above the Post box as well as above the whole main wrapper and the header. See the image above.
Once you have added these boxes you can now add adsense (or anything else you like) above the post title by adding the adsense script in the box above the Post.