For documenting purposes it's better if you shoot with a small-sensor camera (smartphone for example), straight-on, with a lot of indirect lightning.
Lightning is number one, I would just use a lot of lamps, with the same color temperature, spread out. A lot of light will also raise the f-number (unless you do that manually), which increases the depth of field (DOF).
Where the light is a point source, use some diffuser, like a piece of paper.
Shoot at angles where the light does not reflect directly on the surface, takes a bit of experimenting.
A flatbed scanner cannot be beat if you want to get direct dimensions, but is has a very shallow DOF.
Second thing, after light: learn to adjust exposure. Shadow areas should have enough information, light areas should not be pure white (overexposed). Shoot in aperture priority mode (if available) to lock the DOF.
Third thing: this also deals with light, but make sure you have a rich color. This will help you in post, as you can just hit Shift-U in Irfanview and auto-adjust everything. This means staying away from cheap LED lights or older CFL bulbs. You should look out for lamps with >80% CRI (5000K-5500K preferably). Or shoot in daylight.
Other things:
- you need to experiment a lot and always study the pictures on the big screen, not just the smartphone or camera LCD. Those lie.
- for fast, temporary uploading, the best to use now is imgur. You can just paste an image from the buffer or print capture, no registration required.
- for long-term usage, Google Photos is hard to beat. It automatically uploads, has nice adjustments and easy sharing. But not anonymous.
- even with steady hands, your photos can be blurred. So either take at least 3 photos or invest in some tripod/mount
- use a grey background (such as a cutting mat). It will help your camera from over/under-exposing and keep the focus on the piece you are trying to shoot
- use digital zoom (sparingly) to get a straight shot. A lot of cheap cameras distor at the edges. It also decreases macro distance, so it lets you see small lettering.
- if you have a shallow DOF, focus on what you want to show, not everything
- crop and zoom in on the significant/useful bits, keep the other stuff blurred or away
Random examples, pulled from my Google Photos archive:
http://imgur.com/a/oSdcJ