Estimation methodologies for SSRS in particular or Business Intelligence in general can vary based on the size and complexity of the project.
Books related to effort estimation methodologies in general or SSRS/BI in particular. Add books' link here.
Articles related to effort estimation methodologies in general or SSRS/BI in particular.
Other links for community resources SSRS Design Patterns http://social.technet.microsoft.com/wiki/contents/articles/11324.ssrs-design-patterns.aspx
Aalam Rangi edited Revision 3. Comment: Fixed typos.
Aalam Rangi edited Revision 2. Comment: Fixed typo for "vary".
Aalam Rangi edited Revision 1. Comment: Adding Design Pattern wiki link.