What this assumes:

• You know how to get to Central Admin and the Search Admin screens
• Any URLs below you will have to replace “centraladmin” with your own server ip
• The place where you can run incremental or full crawls is:

  http://centraladmin/ssp/admin/_layouts/listcontentsources.aspx

Metadata properties:

• In order to have more columns to search, you must add them to the “Metadata” in the ssp

  http://centraladmin/ssp/admin/_layouts/schema.aspx

• Any metadata property has a 64 character limit when querying using Enterprise Search SQL (ESSQL)
• In order for a column to show up in the Add Mapping dialog an INCREMENTAL crawl is required (column existed and just didn’t have data in… added some data to the list making sure to populate the new fields and then ran an incremental)
• Adding a Managed Property requires a FULL crawl in order to populate the data in that field

Search visibility:

• If a site has Search Visibility disabled, it will show up as a warning in the crawl log. LISTS DO NOT
• Changing a list’s Search Visibility (in advanced settings) will require a INCREMENTAL (full is not required) crawl in order to start showing up in search results

Search scopes:

• Changing an existing search scope requires you to update the scope again
  Go back to Central Admin -> ssp -> Search Settings -> Start Updating
  After clicking Update… it almost always goes from 0% to 100% after a while… no in between
• Changing scopes does not require an incremental or full crawl (you simply need to update the scope again) see above
• For a search scope, to have it include list items your scope should have a “folder” with a value like (encoded url with trailing slash):

  http://moss/sitecollection/subsite/Lists/My%20List%20Name/

Also, here is some very unhelpful microsoft documentation:
http://msdn.microsoft.com/en-us/library/ms493660.aspx

Leave a comment if you have questions!