The size generally works at a 1 to 1 ratio to your monitor, like if you put the pen in the top left corner of the tablet your mouse will jump to that point on the screen, so a larger tablet allows you to get better detail.
The monoprice doesn't come with any drawing software, just a disk with the drivers and some tablet PC software which is kind of useless IMO. I don't know if the wacoms come with software anymore because the last one I bought was about 15 years ago, it came with a disk of out of date software on it, and some trials of adobe products.
Either way you may want to get software separately. Adobe stuff is really expensive and while I use photoshop quite a lot I don't recommend it for drawing. Its line algorithm suuuuucks. It's okay for coloring and painting though if you tweak the settings enough.
If you want something cheaper the new Manga Studio is about $80 and pretty intuitive in my opinion. Paint Tool SAI is also very nice to draw in and costs $50-$60, but if you have a monoprice tablet and dual monitors it glitches out really bad. There's also several free softwares on the market but they usually are kind of lacking in features so I don't use them much.
