Microsoft TechNet - Exchange Server 2010
Configure Client Access Server Properties
TechNet Wiki - How to Configure SSL Offloading in Exchange 2010
Transport Rules

Microsoft TechNet - Exchange 2010: Editions and Versions:

• Standard: maximum of 5 databases per server.
• Enterprise: maximum of 100 databases per server.

Microsoft TechNet - Understanding Memory Configurations and Exchange Performance
Microsoft TechNet - Understanding the Mailbox Database Cache
Microsoft Support - How to modify the Store Database maximum cache size in Exchange 2000 Server

The Exchange Team Blog - Publishing Exchange Server 2010 with Forefront UAG and TMG

Windows IT Pro - Prevent Problems with Exchange Server 2010's MailTips

exchangeserverpro.com - How to Restore an Individual Exchange 2010 Mailbox with Windows Server Backup
Yuval Sinay - How to restore Exchange 2010 Database to Recovery Database (RDB) (also mentions cleanup).
Microsoft Support - You cannot restore an individual database by using Windows Server Backup in Exchange 2010 or in Exchange Server 2007

Microsoft Support - Can't manage distribution group from Outlook with Exchange 2010 or Exchange 2013 mailbox (KB2586832)
The Exchange Team Blog - How to Manage Groups that I already own in Exchange 2010?

Microsoft Download Center - Multi-Tenancy and Hosting Guidance for Exchange Server 2010 SP2
Exchange 2010 SP2 Multi-Tenant Scale Guidance

ITswapshop.com - Creating Tenants for Exchange 2010 SP2 Multi Tenant
Exchange Sender Based Routing

Microsoft TechNet - Resources for IT professionals > Gallery > Exchange > Exchange 2010 SP1 (and later) ExFolders
The Exchange Team Blog - Exchange, meet ExFolders

The Exchange Team Blog - Dude, Where's My Single Instance?
Viral Rathod's Exchange 2016 Blog - Single Instance

Microsoft claims SIS in Exchange Server 2007 only saves 0-20% of storage.

However there appear to be situations where SIS saved more:

I have performed numerous 2007 to 2010 migrations for customers where the DBs inflate by 50% or more. 
An recent example is where 400GB on Exchange 2007 turned into over 650GB when moved to Excahnge 2010.

Source: Microsoft TechNet Forum - Determine SIS in Exchange 2007