Let me be the first to recommend that you read the
Wiki, and the
Cliff notes on this site. LOTS of great information there.
Then, let me highly recommend that you buy a dedicated PC to run
Blue Iris and use that as your NVR. Highly expandable, super configurable, great support, frequent updates, etc. Read fenderman's advice on getting a great refurbished PC for this job for cheap.
As for cameras, if you will want good performance in dim light, the Dahua cameras with 2 Megapixel Starlight sensors (Sony Starvis sensors) are hard to beat. Their excellent low-light performance makes them superior to higher pixel-count cameras in low light, and that is frequently what you really need because a lot of crime happens at night when the light is less than ideal.
License plate reading is difficult and a subject that has its own section here. Don't expect this to be easy. And the same really goes for good facial recognition. You need to have enough pixels on the subject, and proper camera angles to get court-acceptable images of faces. Looking down often only gets you a nice shot of the top of the perpetrator's hoodie. I never realized how bald I'm getting until seeing my own security cam footage of myself! I don't look that way in the mirror!
All of that means needing a lot of cameras to really cover the areas well. I don't have nearly enough coverage yet in my system, but I am trying to add more cameras as I get the time and disposable cash to add things.
The cameras a lot of us prefer operate on POE (power over ethernet) as you've requested, because you only need to run an ethernet cable to the camera location. But you want to buy good quality solid-copper conductor cable, not copper-clad aluminum. POE demands good conductivity to handle the power, and non-corroding connections to keep things cool, so stay away from cable with aluminum core conductors.
Of course, you will need a POE switch to power the cameras and connect them. Get one with a LOT more channels than you can ever imagine needing. You can never have enough cameras.
Think carefully about where you are going to put the switch. It needs to be in a climate-controlled location so it won't get too hot in warm weather. Heat is the mortal enemy of semiconductors and especially electrolytic capacitors.
You will also need a place for your Blue Iris PC, too. It is really nice to have space for a keyboard and mouse and a comfortable place to sit when setting things up on it unless you are going to remote into it. If you have the space, I'd just set it up as a small workstation just for convenience when you are adding cameras, etc.
Eventually (or immediately!) you may want a router for your home that can act as a VPN server. The higher end Asus routers are very nice for this. It is great to be able to connect securely to your home network to view your cameras remotely from PCs, phones, tablets, etc. Using a VPN to do this is just about the only way to accomplish this without using dangerous port-forwarding, etc,.
Most cameras and NVRs will, by default, want to port forward to give you remote access. But it is extremely insecure and dangerous for your entire network. So assume from the beginning that you will not use the built-in capabilities of the cameras or NVR to do this. It is not safe.
Lots of folks will help you through all of this on here. Have fun!
All of this is covered in the Wiki and notes.
