I would buy your SSD first. You only need enough capacity for your operating system and programs. For most 120 GB is lots, and 250 GB is really lots. Samsung has just released the 840 EVO SSD's in those capacities, and they provide high performance at a good price.
1. Unplug your existing C: drive.
2. Physically install your SSD, but read this
Optimization Guide first. On your first boot up go into the BIOS and make sure your Hard Drive controller is set to support AHCI. Make sure you use a primary controller SATA port for the SSD.
3. Allow a full boot with your Windows 8 OS disks in your optical drive, and install Windows 8 on the SSD (C: drive).
4. Plug in your old HDD, and boot up again. Windows will recognize it and install it as D: drive.
5. Look up how to move the Library files in Windows 8 to your D: drive. (You are really just pointing to them).
6. Copy your old data into the new libraries, although if you do the "Move" naming right you will not have to copy much.
7. Delete all the Windows and Program directories (after you save any data, like e-mail, favourites, etc) on D:.
8. Install your programs on the new SSD C:
That is just the basic steps. If that does not make sense, then do more research. It is not all that easy to do it right. Your main objective is to make sure you have a copy of all your data safe before you do any deleting.
I don't see any point in saving your Windows 7 recovery partition. However the programs are another matter. You want to save them somehow if you do not have the original installation disks to use. I have not worked with partitions for a long time, and don't know if you can move them, or delete them? To get the most use out of the old HDD you will want to get rid of the partition, and that may mean getting everything off it first.