I have a site that I created with the VSD that I would now like to move to a Wordpress site. The website has been live for 3 years and I don't want to mess things up too much with the SEO, so how do I go about doing a 301 redirect? Thanks for the help!

You would need to do a Change of Address via your Google Webmaster account. This will ensure that Google moves all your rankings to your new site. Now, if the web address does not change then you do not need to do this.

If you are only changing the content of the website and the URL is staying the same you would simply do a 301 redirect for EACH page to its respective replacement page. Yes, this means if you have 200 webpages in your site you have to do 200 redirects (unless some of the page names are staying the same). If you do one wildcard redirect such as:

www.mydomain.com/contacts.html redirects to www.mydomain.com you lose ranking with Google because you are not linking to a relevant page.

You do not need to however create 200 pages on your new site, but the new page needs to be to a page that has mostly the same information as the page that is being redirected.

Example:
On you old site you had two pages called dog-grooming.html and dog-washing.html.
If you combine Dog Grooming and Dog Washing into one page on your new site called dog-services.html you can then redirect both dog-grooming.html and dog-washing.html to dog-services.html and so on.