You need a good test kit, so you can stop going to Leslies.

Seriously, it's the best way to take control of your pool and keep track of your water balance. IF you are going to go the SWG it's essential.
The salt test strips are okay and actually preferred. Regular test strips for other chems are not. Get yourself a TF-100, you won't be disappointed.
You can add the salt and start your filter, I think I read you need to wait a bit and make sure the water is balanced properly before you turn on the SWG unit though.
About closing and winterizing an SWG - I don't know.
What I do know is the last 2 closings I have added nothing to my pool except bleach, no "winterization chems" that Leslie's and the like sell to unknowning buyers.... and I've opened to crystal clear water twice and I looked under my winter cover now and it's crystal under there. If you read the ingredients label on the "winter kits" you'll see they are likely unnecessary for a properly balanced pool. I think the store by me sells them for $40 to $50 depending on the size of your pool, and they really are just a waste of money. Granular chlorine, algaecide and alk increaser. Other than the chlorine, I don't need to add them, especially not $50 worth.
Someone will chime in about the winterization process for an SWG I'm sure. In the meantime, read all you can about adding salt, make sure you get the right kind, and go for it.
