How does it work? You contact me and let me know what you have in mind - let me know what type of pose ideas you have such as hobbies, occupation, personality quirks, what you would like in the background, I can add logos and phrases, etc. Most people have me do full action poses like most of the samples above, but I can also do just faces from the shoulders up. Usually I do them in full color but I can also do them in B&W, with or without shading. I can put as many people as you'd like in on page - one time I did 50 people! You let me know what the size of the printed work should be, most people choose standard frame sizes (such as 16" by 20", 18" by 24" or, 20" by 30" or 24" by 36") so that you don't need a custom frame. 
I'll probably have more questions for you after you contact me, I may have some ideas for you. I'll give you a price quote based on how much time I think it will take. For one person in color with a full action pose and some background it's usually between $150 and $250. For B&W caricatures or faces only, the fee will be roughly $50-$125 per person. The fee is not affected by how big the finished image will be since I do them digitally. Yes, there are other caricaturists who charge less than me or have set rates listed online, but I don't crank them out with a formulaic approach like some do, I take my time with these, customize them as much as possible and make changes to them as requested so you are happy with the finished piece. A deposit of 50% is required, balance due on completion. Payment via Venmo, credit card, or Paypal. 
To start off you email me some photos, I then create a digital rough sketch based on your ideas and email it to you. Often at that point you will have changes or additions for me. For example, you may ask me to make the chin less pointy, have the person holding a wine glass, add some palm trees in the background, etc. Then I create the first draft of the finished work and email it to you, but even at that point you can still request changes. When the work is done I email the finished work to you as a very high resolution jpg file (or other file formats on request) and you get it printed at your local photo developer or an office supply store such as Staples, preferably on high quality photo paper, any size you'd like. And of course you can post the images online! More info here.