I've used Foscam IP cameras with a Synology NVR at home and really believe you'll end up knowing more than you want to know to set one up right. Plus once I got over 3 cameras I had to set up a second network because my first network was taking a bandwidth beating. Nothing wrong with going this route but you could dump a lot a money before knowing it.
When I worked in one of our manufacturing facilities we used high end $1,000+ Bosch cameras and NVR systems using analog and IP cameras. I mention this because as some would know you just don't add cameras on the fly. You calculate out cost, disk space (how many days are you required to have on hand), switch routing, ...
We had a couple plant managers that wanted cameras on the fly to put in their driver waiting rooms and other nonessential spaces and went out and bought a couple Swann DVR systems that came with cameras for us to setup on the network and have maintenance install.
Like this:
http://www.amazon.com/Swann-Channel-...+camera+system
For the price, picture quality, ease of installation, and network setup I was impressed. Since moving I've given all my Foscam cameras away and will be adding one of these systems. This time I'm going simple!