You have many choices available to you. You will certainly want a development SharePoint environment, and this can be installed on a Windows Server 2008 virtual machine, or directly on your Windows 7 installation along with Visual Studio. This is a little trickier to set up, and you won't have the convenience of being able to roll back your environment using snapshots. It really is a personal preference which way you want to go (I use the Windows 7 approach because I only have 4Gb of memory on my laptop). You have enough memory to make installing in a VM an option, but you still might want to have all 8 Gb available.
You might also consider installing Windows Server 2008 instead of Windows 7 if your workstation is purely for development and you have another machine available for day-to-day use.
Whichever way you go, be sure to avoid the "stand-alone" option when running SharePoint setup, even though it is "just" a development environment. Install SQL Server or SQL Server Express (with tools) separately and use the "Server Farm" install option.
Setting up development environment on Technet
SharePoint 2010 Development
Sahil Malik's blog