Since my company is small I use two Canon camcorders, the HV30 & HV40. The viewfinder on these cameras is in the back and harder to look through and the flip out viewer is also small, about 2.5 inches. Having on camera monitors gives us a better view of our shooting area and can help with framing.
The Haier 7 inch HLT71 is an excellent choice if you are on a budget but need good monitors for your cameras. The video below, produced by DSLR Film Noob is a terrific review of this monitor.
You will notice he mentions the screw in the bottom of the monitor is not quite the right size but I have found I can screw in a Cold Shoe Adapter enough to mount the monitor.
The monitor has stereo audio inputs and a video input, all RCA connections. It has very good color and is bright, however you will want to make a hood for it if you shoot outdoors or in bright light conditions. Plus it has a handy headphone connector so you can monitor the audio of your recordings while shooting.
It also comes with a remote but when using it as a monitor it probably will not be needed.
Since the output of the monitor is directly off the HV30/40 I can monitor the audio levels on the monitor itself as well, giving me a clear view of my volumes.
The battery lasts about 2 hours and it comes with a charger. You can run it off the battery or plug it in if your camera isn't going to move much.
Watch the video below and if you need a good monitor but you are on a budget, the Haier 7 in HLT71 is a good alternative to buying an expensive one.