Your laptop's line power unit should be able to handle 100-240 so no problems there. Both 2- and 3-prong outlets can be found, so either bring a universal adaptor or pick one up in China (any supermarket, convenience, department, or other store will have, and many hotels will let you have a loaner if you forget).
Usually you'll find available wireless networks will show up in English on your laptop--many locations for free wifi now in major cities in China. Most of these are unsecured networks, so don't do sensitive personal business on an open channel.
The one thing that is very different from using a laptop in the USA and other "free world" countries is the net blocking/Great Firewall of China. An investment in a decent VPN (the SSL type) is a good idea--get a techie friend or colleague to help you with this if you are clueless in this realm, and have it installed while still in the USA.