Clean install of Windows 7 on new SSD

I'm not sure what you mean by "without having to offload everything else that's on it." but you'll have to re-install all your programs. Here are the basic steps.
1. Install the SSD and disconnect the hard drive.
2. Install Windows 7, drivers and install Windows updates.
3. Configure Windows for SSD use by disabling the Page file if your PC has enough memory. Configure Defrag so it doesn't access the SSD. There are tutorials for this.
4. Re-connect the hard drive and boot Windows.

At this point you should be able to see the HD and your data (Users folder). If you're never going to boot the old HD again you can: Delete the Windows folder, Program files folder and a few other files on the root of the old HD. Make sure you don't delete the "users" folder. Your profile and data are in there. I suggest moving all your data off the HD and format it. When you re-install software you can re-direct installs to the HD.

Thanks DeadRam for your answers - I did as you suggested, in conjunction with a couple of the guides on the site, and now have a perfectly functioning Win7 SSD and a nice clean data drive. I love how quickly the machine boots and applications load - it's like having a new PC!

The one disappointment was that I only later read about the shenanigans you have to go through to move the default user location to a drive other than C:, and that it can only really be done during the installation. I've use the inbuilt options available to change the location of My Documents, etc, but will still have to "fight" every application install to keep it's data on E: instead of C:!