I'm looking for some book about SQL Server 2008 and T-SQL, let's say intermediate (focus on stored procedures, indexing, optimizations, performance), not taking too much on simple create/insert/select ;)
It will be also great with some .NET featues, also on improving performance mainly.
This is my favorite book for touching on a little of everything (and providing references to where you can find more detailed info):
MCTS Self-Paced Training Kit (Exam 70-432): Microsoft® SQL Server® 2008 - Implementation and Maintenance
ISBN 13: 9780735626058
I like the test-prep books in general -- not that I take the tests usually (unless I'm updating my resume), but just because they have pretty good coverage, and a lot of good references.
Otherwise, the 'Inside Microsoft SQL Server 2008: T-SQL Programming'
Inside Microsoft SQL Server 2008 T-SQL Programming (Developer Reference)
ISBN-13: 978-0735626027 ISBN-10: 0735626022
or TSQL-Querying
Inside Microsoft SQL Server 2008 T-SQL Querying (Developer Reference)
ISBN-13: 978-0735626034 ISBN-10: 0735626030