I want to use WebP--https://developers.google.com/speed/webp/?csw=1
I think it comes as a plugin from Telegraphics
but I'm not sure how to install it into Adobe Photoshop CC. I also am running a Windows 7 machine. Any advice?
This question probably belongs to the graphic design stack exchange (http://graphicdesign.stackexchange.com/), not here. Anyway, you have to copy the plug-in file inside the plug-in directory you can find in C:/Program Files/Adobe/Photoshop CC/Plug-ins, restart Photoshop and you should be able to open webp files.
Note that you have to check what version of Photoshop you are using (32-bit or 64-bit) and use the correct version of the plug-in for each case.
It is possible that you have both versions installed in your computer so you should better copy each version of the plug-in inside the corresponding photoshop plug-in folder.