How to save links from an old website when building a new website even if the site map changes?

[Doug_Hay]

I have a client that needs a new website with better navigation, etc. The site has been up for a number of years and has backlinks that I would like to keep when building the new site in WordPress.

[peterthistle]

I've used this Redirection plugin a couple times  on smaller sites, makes it about as easy as possible.

[RAN_SEO]

Great answer Ryan. One more important note, If you also going to change the domain name it is important to let google know about it in google webmasters tools.

[AdoptionHelp]

If its possible to fix the site without altering the directory and URL structure, that's going to be your best option.

However, I'm guessing you're going to be fixing URLs as well, and if that's the case you'll want to use 301 redirects to tell search engines where the content has gone. See http://www.tamingthebeast.net/articles3/spiders-301-redirect.htm

Finally, wherever possible try to get the owners of the sites with backlinks to update their links to you.