Security Camera Recommendation

[William Price]

I want to have some security cameras installed at a duplex.  One of my tenants has kindly offered to let me piggyback off of her internet.

I'm thinking I need 2 cameras out front, 1 on the side and 2 out back.  Does anyone have any recommendations as to what system to put in place, name brands, cost, etc.  Also,  I'm guessing I need an electrician to install the cameras, but perhaps they are wireless now.  

I'm starting from scratch with the research on this so any insight other can provide would be most welcome.  Thanks!