There isn't a "MOSS 2003".
Please confirm that what you actually have is SharePoint Portal Server 2003 (or is it perhaps Windows SharePoint Services (2.0)?)
It's unclear to me exactly what you are "migrating" and from what. "SQL Source" ?
SP 2010 "FAQ" (mainly useful links):
http://wssv4faq.mindsharp.com/default.aspx
WSS3/MOSS FAQ (FAQ and Links)
http://wssv3faq.mindsharp.com/default.aspx
Both also have links to extensive book lists and to (free) on-line chapters