301 Redirect for complete site to new url

I am in need of some help and after consulting with google webmaster tools, i’ve determined that I need to do a 301 redirect. My current blog with nearly 3,000 posts and 100 pages will have to move from its current domain to another domain. I have had the site up and running for nearly 7 years and have managed to gain a very friendly stake in search engines which drives a ton of traffic to the site. I would like to retain as much of that as possible but, as mentioned, i’ll be moving everything to a new domain name. Any help is greatly appreciated. I will have access to both domains for as long as I need.

Thanks so much.