Unique Identifier as Clustered index

This script selects clustered indexes containing only a uniqueidentifier column

Find the size of all Indexes in a database

This script finds the size of all indexes in a database along with the table and the filegroup on which the index resides.

Script out/store all indexes on a server

This script will store all index definitions into a table that you can use to "re-create" the indexes at a later date.

SQL Server: How Important Are Index Statistics

In this article Greg Larsen will show you how to identify when your index statistics were updated last, what method was used to gather statistics, and how to update your statistics.

Indexing

Reindexing for fragmented indexes

Script will give you the list of fragemented indexes.
(For SQL 2005-2008)

Precision Indexing: Basics of Selective XML Indexes in SQL Server 2012

Seldom has a SQL Server Service pack had such an effect on database development as when SQL Server 2012 SP1 introduced selective XML indexes. These transform the practicality of querying large amounts of XML data. Seth Delconte demonstrates how and why this feature makes all the difference.

Reorganize indexes for all tables in all user databases

Script to reorganize all indexes on all tables in user databases

SQL Server Performance Tuning – Index Tuning

In earlier installments of this series we looked at T-SQL Performance optimizations along with different T-SQL practices, we can now turn our attention to the second part of this series which is index Tuning

Script to Rebuild/Reorganise Indexes

A script to get the fragmentation of indexes in a database and then rebuild or reorganise accordingly