Help!

I am redesigning my old table based site to CSS with Dreamweaver and would like to add a few things. I am looking for FREE (I am over budget) and easy ways to add these features to my redesigned site. Specifically: (1) A search box for the site only with no advertising on results page, (2) Breadcrumbs, (3) A new navigation system. I am particularly concerned and clueless as to the best way to do the navigation so as to be search engine friendly, easily updated (I will be adding 10-20 pages a month after redesign is complete), go 4 levels deep, & accomodate other navigation bars on the same page. I have found a number of candidates to accomplish my goals, but I really don't know whether they will do what they say or if there are better choices. I imagine some of you out there have experience in these matters and can stop me from making any major mistakes. I would appreciate any help or guidance that you can share. Thanks!

Here is a list of most every commonly available open source content management script:

http://www.opensourcescripts.com/dir/Content_management_,040CMS,041/

Thanks for the quick reply! I will take a look at what is offered over the weekend. Any suggestions on what to focus on? Thanks again!