Problem with MAMP. My Mac's local host can't find root folder htdocs nor its contents. Help?

Running Mac OS 10.5.8
Trying to set up local host.
Have MAMP installed OK.
Configured root to folder name htdocs
File show up fine on my Mac directory under MAMP
with all my drupal 6.x files, etc, and a test index.html I put in to test.
When I navigate to http://localhost:8888/MAMP, MAMP shows up fine.
however I get a 404 page saying can't find any page I put in.
E.g. http://localhost:8888/MAMP/index.html, my test page, causes a 404.
Nothing in htdocs will open, nor can I open htdocs itself.

What am I doing wrong?

Thanks in advance!

Mike Storer, Los Angeles.