Any ideas about security cameras?
You should probably get some. Harbor Freight has a 8 channel security DVR that comes with 4 cameras for cheap. I have one and the video is very good. Added 4 other cameras I found elsewhere for a better price than HF sells additional CCTV cams.
I got the wired system as I'm use to running cabling in homes. So usually they are less expensive. If you don't get along well with technical computer setup, you probably need to get something more user friendly. It's a beast to set up correctly and use all the features it's capable of.
I have the doorbell cams too, front and back, but I'm less happy with them. Well placed CCTV cams can show a lot more.