Below you find my most valuable SQL Server and database related links. To make it a bit easier to find what you are looking for, I have categorized the links. Click on a category to display the links.

Give feedback, report bugs etc ( is gone as of 2018):
SQL Server feedback forum

Miscellaneous SQL Server web sites

Glenn Berry's SQL Server Performance, including DMV diagnostics queries

Erland Sommarskog's in-depth articles about dynamic SQL, arrays in SQL, error handling etc.

Brent Ozar, sp_BLITZ

Ola Hallengren's solution for SQL Server backup, integrity check and index optimization

SDU Tools, lots of useful functions from Greg Low

SQL Server KIT, including trace flag list, Konstantin Taranov

Stairways on SQL Server Central

FAQ availability groups, Sean Gallardy

Versions of SQL Server

Most recent update of SQL Server

Version history,

SQL Release Services Blog, find recent releases

3:rd party products that I've found useful

Data modeling tool, SqlDBM

ApexSQL Log, retrieve data from transaction log

Tiger Team's toolbox

SysTool's SQL Log Analyzer

Poor TSQL Formatter

Performance monitoring tools

Stuff you pay for.

SQL Sentry
Quest Spotlight
SQL Monitor

Free staff that are easy and simple enough so you can tweak them and "make them your own" with the changes you make.
Erin Stellato's performance logging solution

Free stuff that are more "closed", in the sense that complexity, hiding source code or similar gives you limited "tweakability". There is a grey line between below and above, obviously
Periodically collect performance data and visualize it using Brent Ozar's solution

Database Health Monitor from Steve Stedman
SQL Server Tiger Team's performance monitoring solution Has a couple of bugs  (storing the collected data as varchar and using comma as decimal separator along with an inefficient table design for storage) and doesn't seem to be any active development, unfortunately.
Clint Huffman's PAL

Other related stuff
Best SQL Server Performance Monitoring Tools and Software Comparison and Reviews
6 Best SQL Server Monitoring Tools for 2019
Free SQL Server Load Testing Tools


Home page (check out the blogs from the members)
Wait Types Library
Latch Classes Library

SSIS related

Component listing on Codeplex - By Darren Green and Allan Mitchell


SQL Server e-book gallery
SQL Server virtual labs
SQL Server Licensing
Microsoft SQL Server Home
Connect: Microsoft SQL Server Feedback
Database Engine Permission Basics

General databases

Library of Free Data Models
Database Debunkings
The Data Administration Newsletter ( Foyer

General stuff

NIST Dictionary of Algorithms, Data Structures, and Problems
Sysinternals utilities
Dependency walker