A good primer on the difference between WSS and standard ASP.NET webparts

http://blogs.msdn.com/dmandreev/archive/2006/12/07/wss-3-0-webparts-development.aspx

A good BDC definition primer

http://blah.winsmarts.com/2007-4-SharePoint_2007__BDC_-_The_Business_Data_Catalog.aspx

BDC configuration example using userid and password in connection string

Paul Galvin shows us a work around so you can pass the userid and password for a connection in a BDC definition file.

http://paulgalvin.spaces.live.com/Blog/cns!1CC1EDB3DAA9B8AA!320.entry?cd9886e8

Custom Web Properties Not Showing in MOSS 2007

http://ph-tom.blogspot.com/2008/02/custom-web-part-properties-not-showing.html

Some SharePoint lessons for beginning developers

http://blogs.charteris.com/blogs/edwardw/archive/2007/07/02/sharepoint-web-part-development-lessons-learnt.aspx

Error 1 - Deploying a WebPart solution

Problem:
Error 1 The solution can not be deployed. Directory "DataView" associated with feature 'ad6ebc94-517f-4653-be15-84ceb207f5ec' in the solution is used by feature '99088a73-c387-4c4b-94be-a73353a270da' installed in the farm. All features must have unique directories to avoid overwriting files.

Solution:
Go into Central Administration, Operations, Solution Management and retract the solution.

I had this problem when using the VS2005 SharePoint Extensions after I deployed a solution the first time, changed the solution and then tried to deploy it again. I'm not sure why I had the problem, I would think I could edit and redeploy again and again.

Web Part Gallery Groups

How to add a group designation before you import your webpart into the SharePoint Gallery.

http://blog.maskar.net/2007/06/wss-30-web-part-gallery-groups_14.html