Sayvari,
I would say first, it depends on the quality of the site you are looking for, and who your prospective market is.
For beginners, I would definatley recommend you do not start off creating your corporate identity as a web site until you have some practice - since prospective clients are apt to visit, a bad representation can do more harm than good.
With that said, I would first play around with any of the above refrenced WYSIWYG editors and create a personal page - maybe about your family --- that I would say would be fine for publication to a Yahoo! (Geocities) spot.
For your business, I suggest purchasing your own domain - and hosting. I would never put my business on anything else, that is unless it is product driven, then a Yahoo! Store would be ok.
As for design, as a professional, I create all interfaces for my designs in Photoshop. For a novice designer, I would say get a free version of Paint Shop Pro, and read some tutorials on it. It is really better to create your graphical "look" then integrate your content.
Also, don't give off an amature feel --- stay away from scrolling words, flashing stuff, too many animated graphics, and clip art.
Good luck, and if you have any other questions, I would be happy to help you
**edited for spelling errors