Here are some links that helped me with developing MS CRM 4.0 solutions the last couple of weeks.

Checkbox style Multi-Select Picklist
http://blogs.msdn.com/crm/archive/2009/03/31/crm-4-0-checkbox-style-multi-select-picklist.aspx

Using the Advanced Find for FetchXML builder
http://ronaldlemmen.blogspot.com/2006/11/using-advanced-find-for-fetchxml.html

ReadOnly and Disabled Fields
http://customerfx.com/pages/crmdeveloper/2006/03/06/17312.aspx

Hiding the left navigation panel on a CRM entity
http://marcoamoedo.com/blog/hiding-the-left-navigation-panel-on-a-crm-entity/

Creating Master Detail views in Dynamics CRM
http://marcoamoedo.com/blog/creating-master-detail-views-in-dynamics-crm/

Collapsable Form Sections – a bit of the future in CRM 4
http://marcoamoedo.com/blog/collapsable-form-sections-ndash-a-bit-of-the-future-in-crm-4/

Minimum Dynamics CRM Permissions
http://www.orbitone.com/en/blog/archive/2009/10/06/minimum-dynamics-crm-permissions.aspx