Post installation

Hi there, i'm a complete Drupal newbie so please be careful with me!!!

I'm trying to setup clean url's but the option to enable it is greyed out. If I try to run the clean URL's test I get a 404 error when it tries to find the path... "The requested URL /admin/settings/clean-urls was not found on this server." How do I enable this?

Also, if I create a poll as content, it places it in the navigation menu...how can I stop it doing this?

And finally (for now) is there a file download module for Drupal?

I get the following ugly error messages when I try to do some things, like creating forum containers and forums:

After installing Drupal 5.0 on Mac OS X Server (10.3.9) and testing various settings things appear to be working. The problem is from the Administer, Site Building, Menus list page, several menu items are listed as (disabled). When I attempt to enable them I recieve a blank page and nothing happens.

Any suggestions?

I'm having a problem with some confidential files coming up on Google and I wondered how you guys get round this.

We're using the nodeacess module to protect certain sections of the site, but have allowed files to be public (in our site settings) - as we want most attachments to be accessible to anonymous users. However, I'd assumed that files that are attachments to private nodes would also be private.

I have installed CiviCRM with Drupal and an having a problem w/ "400 Errors mostly when trying to do searches.
Ex.
/user/1/edit/Name+and+Address
/civicrm/group/search?reset=1&force=1&context=smog&gid=1
And a "500 Error" when setting up a meeting
Error loading '/civicrm/contact/view/activity?reset=1&show=1&snippet=1&history=&cid=102' (500 Internal Server Error)

* user warning: Access denied for user: 'gtadna@localhost' to database 'gtadnadb' query: CREATE TEMPORARY TABLE missing_nids SELECT n.nid, n.created, n.uid FROM node n LEFT JOIN node_comment_statistics c ON n.nid = c.nid WHERE c.comment_count IS NULL in /var/www/gtadmn/www.gtadna.schoolaward.it/includes/database.mysql.inc on line 167.