Is this possible?

You can use RAID 0 if your platter hard drives are of identical size. It's best if they're made by the same company as well. You need to enable RAID in the BIOS, and then use the RAID BIOS setup to create a RAID 0 array. This will kill any data currently on the drives. You will also need to install the RAID drivers in Windows. The specific instructions should be in your mainboard's manual.

Note that if one of your RAID 0 drives fails (or if they become unsynchronized), you lose all data on the array. You will need to keep regular backups.

So how would I set up the ssd in addition to the RAID drive?

Faster boot times will be the major impact of the SSD. But unless you are using specialized apps like 3D rendering, movie editing, huge database access, don't expect much out of RAID 0 Hard drives. For gaming, you won't see any thing of significance.

For the installation of Windows, you would have just the SSD connected (Windows gets confused if more than one hard drive or SSD is connected during installation). Make sure it's not connected to the controller you will use for the RAID array.

Once that's done you'd have to connect the platter drives to the RAID controller set up the RAID in the BIOS, install the drivers and go from there.

To be Honest the performance gains of RAID 0 have never been proven to be useful.

I would suggest not doing this, but if you have to go for RAID 1 and protect you data.

What make are the HDD's?