Do you just stick them out of the wall and that's that? Or are their boxes, like junction our outlet boxes used for electrical that can be used?
Eddie, I am mid-way through building my house. I hired a low voltage specialist to do all the internet and camera cabling. I am competent to do all of that myself but glad I hired a professional. To answer your question, anything at a camera location, interior or exterior, has a 2-gang box fastened to a stud. With 4-6 feet of cable hanging out but rolled up and stuffed into the box. That gives you a future option to mount the camera to the box, or put a cover (like a switchplate cover) that has an RJ45 (internet) connector. I would pull CAT6.
You should also consider bringing all of the CAT6 wiring to a central location, regardless of where the cameras are. That central location also needs power, ideally a home run to the panel if you can do that. This is where your electronic equipment will be, either the host DVR, internet switch, etc. Be sure to plan (possibly) for a computer and large monitor in that location as well, if that is appropriate. You will want a single location to go to, view the cameras, download any video you want onto a thumb drive, etc. If your main "media" location is in the future part of your build, you can run a single CAT6 from this location to the new construction to tie it all together.
Regarding POE, that is really nice because you don't need to run a power wire to the camera. I would use the industrial grade internet switches such as from Netgear. Some models offer "managed" switches and offer POE right out of the switch with no separate injector required. Not having to do a POE injector for each camera is much more efficient. (See link.) btw there are other model switches with more POE ports and more power if you need that.
Netgear ProSafe Plus Switch 8 port Gigabit Ethernet Switch with 4 port PoE - Office Depot
Regarding outdoor cameras, dome cameras are attractive but most DIY people don't have the skill to maximize their utility. "Bullet" cameras are pretty simple to install. Anything that you have that is exterior will require you to consider two cameras per location. For example, if you want to watch the front of your house a driveway, one camera could do that. But it probably won't be able to capture a license plate since it has a very wide field of view. If you had one camera for "panoramic view" of the front, and a second camera (with a different lens) that had a real tight focus on your driveway, then you could "watch everything" and capture license plates. Add in night vision, wide dynamic range, varifocal, etc. and there is an overwhelming amount of choices in cameras for a DIY guy like you or me. When you get ready to buy cameras, consult an on-line utility program that will calculate the focal need of the lens. You can measure the width and distance you want in the field of view, and the utility program will tell you what focal lens to get on the camera you purchase. There are also varifocal lenses that are adjustable.
Also, if appropriate, you might consider an external box and CAT6 for a future wireless broadcast signal. On the outside of the house, you could put an internet access point, or nanostation, or whatever and then you could have wireless internet throughout your property. Yes you probably won't be web surfing on your tractor, but when I'm working in the shop I am frequently using a wireless connect to look up part numbers for filters, or research things.
Good luck with your project-- your idea to pull every wire that you can think of NOW is a very good idea ....