Since you are coming to Chiang Mai on Friday you should get your air tickets as soon as possible. The low cost carriers are full of Thai travelers from Bangkok visiting Chiang Mai for the weekend.

On Saturday the 3rd of Feb. is the Chiang Mai Flower festival Parade. very nice.

My opinion is that a weekend in Chiang Mai is not near enough. To learn more about Chiang Mai along with video visit the forum thread "Advice for visitors to Chiang Mai Thailand".

Enjoy,
Randy and Ning