SQL Server licensing is really not easy. To be honest even Microsoft people tend to give different answers for the same scenario in some cases...
- You are giving money for 2005? Why?
-
Depends also on the database size, what is the estimated maximal size? The free Express edition can be also a good option in some cases! Sql Express 2008 has a 10GiB limit. With 25 users this can be enough for years - well, depending on the application.
- To choose proper edition, you will need to compare editions and select the one that fits your needs:
http://msdn.microsoft.com/en-us/library/ms143761(v=sql.90).aspx[
^], but yes Std is good in most situations.
- The version is only one thing. Licensing is an other. You said you don't face the internet, only intranet. Than buying Server license and CALs is one option (you will need probably 25 CALs). Or you can buy processor based license. In case of fewer users, this is more expensive than buying CALs. Short overview:
http://blog.sqlauthority.com/2008/02/23/sql-server-2005-understanding-licensing-model/[
^]
Submit an article or tip