Its not so important until they start to crawl but I would start off looking at things that are low down like stuff lying around on the floor that they can put in their mouth. Then look out for plug sockets, edges and corners, chairs and tables that might not be stable or may be placed somewhere close to somewhere else tempting but otherwise inaccessible. Latches on cabinets, especially where there are medications, cleaning supplies, or knives/tools. Also, if you have stairs, you'll need some kind of gate. We love the adjustable ones that fit anywhere and work by pressure; just press down on the handle and it pushes against the walls.
I can't think of anything else off the top of my head but you'll probably do a great job. The fact that you're thinking about it now attests to you being an attentive parent and you'll be paying attention to your child which is almost more important than any gadget or device.