301 redirects

I have read a number of posts and articles but have not found a clear answer so please excuse me posting this question if it has been answered elsewhere.

I am looking at converting a 5,000 page web site (cooking recipes and articles) to WordPress. It has been built using Dreamweaver.

Obviously this is a job that is not going to be done overnight so rather than build it on the server which hosts the site I intend to build it on my own computer. I have set up WordPress to work on my computer so that is not a problem.

A big concern is over the new URLs and not losing any positions on Google. If I complete the work I will need to create 301 Redirects in a .htaccess file for all the old pages to the new URLs. Because I am creating the WordPress site on my own system the URLs will not be the same as when it is uploaded to the server but presumably that is only a matter of replacing the local directory with the domain name so should not present a problem.

I am not sure if there is a good way of doing this or not. I have seen there are 301 plugins but am not sure what they are intended for. Is there a plugin which would automate the process in that as I converted an HTML page to WordPress it would ask me for the old URL and compile a list ready for putting into a . htaccess file.