No matter what you do you'll need to re-install all of your programs. But you can keep your files. If you have the space on your SSD you can copy all of your files you want to keep (images, documents, music, etc) from your HDD to your SSD. If you don't have enough space you'll have to use an external drive (buy one if you don't have one, or see if you can borrow one from a friend) or you can burn your files to a DVD to copy back to your PC later.
Once you have everything you want to save from your old windows you'll want to re-format your HDD. Open My Computer and right click on the HDD and select Format. You'll want to leave the capacity at it's maximum value (likely your only choice), you want to select NTFS (the default) and set Allocation unit size to 4096 bytes. Hit start at the bottom. This will completely clean off everything from that HDD, if you forgot to copy something over you can't get it back.
Once the HDD is formated you can copy anything you want to store on it back. Make a movie or music folder, use it to install games, whatever you want.
PS. I always forget to do this but save your browser's favorites from your HDD's windows and copy them to your SSD's windows - else wise you'll remember another site to save every so often for weeks.