I've worked with web comic stuff off and on for the past 3 years and I'd be glad to give my two cents on the process and what got me jump started;
My first webcomic is
AlienDrugged, which I have hosted under smackjeeves.
The story is about 5 girls with eccentric powers that have to defend the earth from corrupted alien transvestites. (The girls also have a guardian that is a talking outhouse on fire. Don't ask, this was all made when I was in Jr High! ) Main sources of inspiration were Sailor Moon, Rocky Horror Picture Show, and cheese ball sci-fi B movie concepts.
Second one (which has been on hiatus since the birth of our mother planet) is a collaboration I've done with former voider Lampton/Spinzoa called
Gorge. This one is about young governess and the consequences of befriending a daemon that entices people with sweets and eats them. I did most of the writing and she did the artwork. We have this one hosted through BlueHost with comicpress. Our inspirations come from victorian culture, grimm's fairy tale style structures, etc.
I am currently working on a new one shot called
Tale of the Melancholy Sea Stags which should be no more than 200 pages long or less. I just got the script done and will be moving on to thumbnails soon. I also plan on hosting this through Tumblr and using the simple webcomic theme.
So with that aside, here's some pointers based on my own experience:
1. Know what type of audience you're catering to: What is the genre of your comic? What is the story about? Who is it going to appeal to? This is going to effect the second point which is...
2. Which hosting plan will suit your comic best: Research your options for hosting. For example, I noticed awhile ago that there was a HUGE following for romance, BL, and Yaoi comics on
Smackjeeves. Skim through the 'featured' page and see what gets the most views and fans. Investigate the appeal. The only other web comic hub I can think of from the top of my head is drunk duck, but my knowledge with that host is limited.
Other hosting sites you could consider,
EnterVOID: Like Angie said, you could host your web comic stuff here if you like. Though I personally feel there's more success in doing a series based on your VOID characters since most of us are used to seeing creations within that universe.
WordPress/ComicPress: If you want to go solo and not deal with competition within a website like smackjeeves or drunkduck, you can always try hosting the comic on your own through this kind of venue. Keep in mind you should have some basic understanding of html design (and money, depending on the host.)
Group collectives: You can always band with a few friends and create a website to host your comic projects in! Dapshow is a fine example of such.
Tumblr: Another free outlet for hosting Webcomics is Tumblr! Here's a link to the simple theme as mentioned before;
http://www.tumblr.com/theme/37061 I feel that customizing your presentation with this is less limited in comparison to Smackjeeves.
Lastly, once you figured out the first two steps, the next thing to consider is:
3. How many pages will you have ready before launch, and how often will you update: It is a good idea to get at least a couple chapters worth of material (20+) pages completed before you even start updating. That way if life gets in the way of drawing more material, you'll still be able to post a fresh update in time. Also consider how often you want to update. Most people tend to go one page a week, or two pages a week on different days. This will also effect how much time you'll have to draw new content for your web comic.
For Alien Drugged, I wish I would've completed a couple chapters before starting up. The end result was maybe 2 months of updates, and then 5-6 months of hiatus. :X So I strongly encourage you to get as much done before you present yourself!
As for inspiration in general, go with subject matters that interest you the most! Think back to your favorite movies or stories you've grown up with, beliefs and social issues you feel strongly for or against, etc.
For working out larger stories/plots, I've always wrote down summaries of every chapter, or key events that may happen within certain situations. Sometimes I end up asking for input from my friends to help untangle a plot hole or two.
Sorry for the mass response, but I hope some of this helps!