Change Website to Monetise It ?

I have a site which used to be for local real estate agents. It no longer ranks well for Google for my key words. It shows a Page Rank of 3 on FireFox and I was wondering about changing site to more of a Real Estate blog theme and try and monetise it with Adsense.

Any Tips or Advice, or should I just forget site altogether?

Thanks for any insight

Fix

You have to improve content and build good quality links for it to start ranking and for you to be able to monetize.

If you have content then you can go with adsense for sure, it will require lots of efforts to generate income from adsense. But if you are looking for quick cash just sell the domain.