There are actually a few webcomics done in watercolor which I read and I LOVE them =) Of course there is no ctrl+z, but it has creates a certain ambience =)
As far as techniques/tips...
basically you can create art with the cheapest $1 watercolors, but I'd invest in a good paper (like Canson or HahnemĂĽhle Bamboo Mixes Media) and some waterproof ink you can paint over without messing up your lines!
The paper has to be able to take water and not wave like crazy! This is important!
As for the ink - I have made good experiences with Rohrer&Klinger ink, but that's basically up to everyone's preference =)
I use Schmincke watercolor, they are a bit expensive, but my 1/2 square-thingy-box (don't know what's it called in English) has lases me for ~8 years now, so you get a LOT out of it.
If you don't know where to start: You CAN make epic art with only red, blue, yellow, black and white, just by mixing all of them. I'd def recommend to get a nice green, pink or purple, as well as something like Ochre, too. If you'd like to learn more about my color palette, just tell me, then I'll go into more detail
And just one more preference: I LOVE tank brush pens. They cost a few bucks but they are SO worth it!
You can fill them up with water and don't need a water glass on your table to clean out your brushes, just simply wipe them clean on a towel. I used to spill my water glasses over my art too often, so they are reeeeaaaaally good. Plus: due to the water coming down through the brush, you can make awesome gradients!
That's it for the technical details - are you interested in general drawing tips and techniques, too?