I had previously blogged about some great step by step guides for Remote Desktop Services. I wanted to add a couple more useful links for a load simulation tool and a capacity planning document.
Remote Desktop Load Simulation Tools
The Remote Desktop Load Simulation toolset is used for 32-bit and 64-bit (x86 and x64) server capacity planning and performance/scalability analysis.
Remote Desktop Session Host Capacity Planning in Windows Server 2008 R2
Use the RD session Host role service to allow multiple concurrent users to run Windows-based applications on a remote computer running Windows Server 2008 R2. This capacity planning guide describes the most relevant factors that influence the capacity of a given deployment along with methodologies to evaluate capacity for specific deployments.