Hi HyperGirl, well, here are a lot of people who have gived a lot of useful tips
I'm using a Wacom Intuos3 A5, it have like 4-5 years old and it was a bit expensive when I bought it but it worth all the money I paid. If you're going to make art as a hobbie you can buy a wacom bamboo, it's not expensive as an Intuos and it's very great even for high works. If you're going to make professional art, first you can start with a tiny Wacom Intuos (like A5).
If you're going to use a mouse, yes, you can, it's a bit difficult to start with tablets but it helps you get better drawing freedom and also it takes less time to complete a drawing. With mouse if you want to have great linearts you can use in photoshop the pen tool, or try with Illustrator. I've drawn for several years with mouse but really I progressed more with a tablet.
I used a tablet once, but the magnetic field it uses is a weak version my hands put out, and makes the tablet useless.
I have never had a problem drawing with a mouse. I am actually very fast at creating art because I don't try doing everything the hard way, just because I an use to doing it that way. I adjust. Digital art works better if you fill and draw, and if you want lines you have to fill shapes first, just to do it quicker for the programs.
I was on the phone with a company that wanted me to draw a scene, but before they started describing it, I asked them to give me a chance to open Photoshop. When I was ready I said start. They described everything they wanted and I drew everything at the same time. There was a little lag time but when they were finished I save and asked them for their email address so I could mail it to them. I couldn't tell if they liked it because they were speechless, but after a while they said they thought I was drawing a sketch not a finished image. I said the finished image is easier than drawing a sketch or a bunch of lines, because the program don't work that way. So they payed me and gave me a WOW rating, because even the simplest things made them say wow for days.
I worked freelance, and any company I wanted to work for I created sample art, and sent it by e-mail so they could write back. Everyone I sent art to replied and even if they didn't have anything for me to do, they created a new project just for me. It seems like a lot of companies like to call me direct and talk person to person, but I still like email better, because I don't need to answer it as soon as it is sent, and I never need to wait. They don't always make an appointment to call. They just call until I am home. The first call I got was from a company in China asking me to send them some of my art to put on a CD before they plastic rap a program.
I get some from England, New York, and California, but I stopped sending sample art and the jobs stopped. I had my moment of fame, and now I want to do something that pays a lot without looking for work, like computer programing. I did a lot before but I am going for a degree now.
All the art in my gallery is made with a mouse. Sometimes people even wonder how I draw so well with the mouse. It took me more than 4 year to master it just a tiny bit. The mouse is a real pain in the hand. I'm waiting for a tablet too btw.
Wacom intuos4 large all the way. It's fairly huge and I regretted not having bought a medium because of this initially, but now that I'm used to it, I like it a lot. Using a mouse for digital art is equivalent to using a machete for surgery. It can be done, but it's rarely pretty.
I wish I'd mastered it all I've had a tablet for a while, but I've only been using it "seriously" for like 4 years now. It's gotten to where I'm more comfortable using that than doing traditional art with pencil and paper