what he said - BUT:
generally the more expensive printers are easier to use and don't require quite as much knowlege to use and don't need as much modifying to make it work properly.

Probably the best way to start is work out what the maximum size of thing you are likely to print on a regular basis is.
Also - bear in mind if you are wanting to make bespoke parts - like an unusual light switch cover - you will need to be able to usea pair of digital calipers and reverse engineer the part from scratch, your self !

The printer is the last step in a chain that goes:
design the part, or find it online > load part into a slicer > send sliced file to printer > hope it prints :-)

The slicer is probably the most important part of the chain, it's the bit that takes a solid 3d model and reduces it to a series of reallly thin slices that the printer can lay down.

Different slicers work better depending on what printer you have.

So before you buy a 3d printer - make sure you can design the models to print. Or get them designed for you.

As far as stringy or fuzzy prints goes. That's why they invented sanding blocks, mini-files, drills and paint :-)

I find that you can print at really high resolutions and take 8 hours. Or print faster and at a lower resolution in 2 hours and then spend 10 minutes doing a bit of post processing and end up with a part at least as good :-)
Once you've got a a few machines you can use them for different things.
But if you've only got the one, you need to prioritise your build time.

So.
1) work out what the largest thing you're likely to print will be
2) get some practice with 3d modelling - I use openscad: http://www.openscad.org/
3) decide on a maximum budget - around $1000 will give you lots of options for some serious machines
4) come back to us :-)