There are a few steps to making a webcomic:
- Get Hosting: I personally recommend ComicFury (www.comicfury.com), as it requires little ID and is the lightest in hosting restrictions I've found.
- Get Tools: Do not pirate/use educational versions of Photoshop or Illustrator (or any other commercial product) to draw a webcomic. If you make any money off of it, you can be in trouble. Use GIMP, Inkscape, or another free program (I just listed my two favorites), since there are so many. If you want, you can even make a pixel-art webcomic, though it's difficult, so use what you have and are familiar with, unless you're aiming for style.
- Get Published: Put up comics. Just don't make it in Paint, and you should be fine. (You can if you're good enough, but not even Chuck Norris is that good)
- Get Readers: Put out links. Bonus points if you can put it on a site that people read your stuff on a lot, or whose subject is very much like the subject of your comic.
- Optimize: Eventually you will probably want to redraw or optimize much of what you've made.
Here's some additional fine points.
- Some formats allow interlacing. It's a wasted feature, if you ask me, in this age of cable. All you will do is make it impossible to load your comic. This nearly killed some episodes of my old comic, because it took a good minute for a B&W PNG to load.
- Use a tool with antialiasing. I didn't for some of mine, and it shows. Use "brush" tools (in GIMP and Photoshop), or use vector tools. If you draw in Flash, be sure to set export quality high. (Though I'm not terribly familiar with Flash, so don't sue me if I'm being vague here. It's a function, I just couldn't walk you through finding it.)
- Use a subject you can write for. Daily sci-fi works for Howard Tayler or geniuses, but a lot of people can't draw or come up with a plot fast enough to run a daily. Humor is an easy daily. Weekly comics are easy for beginners.
- Perfect your style before you start, and if you do go on hiatus to improve your style, release snippets of your work now and then.
- Talk to your readers, and let them know what's happening.
- Keep a queue ahead of time. Two weeks is good, though you could decrease it (at the cost of safety) for less frequently updating comics.
- Get an artist friend. Whether or not you can draw, you can have them draw for you if you go on vacation/hurt your hand/can't draw for any reason.