How much can I upgrade a white Macbook late 2006 & how to do it without functioning optical drive?

I have a white Macbook late 2006 that I want to update as far/much as possible to give to my in-laws to surf the internet mainly so they don't have to go purchase a new PC crappy laptop just to get online. They won't be playing games or streaming movies or running a lot of software - they will primarily use it to look up things online and to browse Facebook to keep up with their kids/grandkids who live away.

I've updated the RAM to 2 gb successfully but I don't know what the latest version of OS I can actually upgrade to is after reviews it seems I cannot get Mavericks to work on this model because of the 32 vs 64 bit issue. I have purchased the Snow Leopard install cd from apple but cannot even get my optical drive to load it and when I put it in it spins for about 10-15 seconds and then spits it back out. I'm going to try to clean it based on some suggested fixes to this problem I read in the community but if that doesn't work I'll need to figure out how to load this into my old macbook. I have a Macbook Pro (2011 I believe is the year I bought it) and I think it may be possible to use it to load the software onto the white macbook with some sort of firewire and booting the old one it target mode which I'll have to learn more about.

Any help is appreciated as to what are the best steps to take to get all this accomplished and if there is any way to get a newer version of the OS X onto this beyond Snow Leopard.

Thanks in advance!