I start with a script (which is a mish-mash of dialogue and descriptions of what happens in a scene, including occasionally pointing out what things should be close-ups or whatever), and pre-design major characters and settings before I start drawing. I started out trying to draw a batch of pages at one time, but that just got confusing and frustrating for me, so I settled into a comfortable rhythm of drawing one page from blank to finished every week.
First, I thumbnail out the page in my sketchbook, nailing down the storyboarding and dialogue. Sometimes this is easy and goes quick, and sometimes it fights me.
Then I draw out my panels, throw in 'lumps' for where my characters and important visual elements need to go, and draw/write in the word bubbles, making sure the art and word bubbles are balanced in the panel. Then I ink the panel borders and word bubbles before I ever start on actually drawing. (Since I'm working on actual paper with traditional media, I hand-write in the text on the page, but I erase it later in photoshop and type it back in with a font I made of my handwriting-- I just like having the text on the actual page, too, because I like to be able to flip through the finished pages later and read them.)
Once the panels and word bubbles are inked, I rough pencil in the actual art, and then go over my pencil lines again with a darker pencil to clean them up. Then I ink them with Micron pens, erase my pencil lines, and start coloring. This is easily the most time-consuming part, and routinely takes me at least a couple of days. Once I'm done coloring, I go over my ink lines again to clean up edges and darken lines that got faded in the erasing/coloring process. Lastly, I sign it.
Then I scan the pages. Since my scanner doesn't do 11 x 17 inch paper (I've never heard of a home scanner that does... I'd seriously consider investing in one, otherwise), I have to scan it in chunks and align it in Photoshop. Then I color correct, remove blemishes, darken the panel gutters, re-add the text, and size it for whatever platform it's being posted on.
Once all of that is done, the page goes to live in its final home, the portfolio I keep my finished comic pages in.