Webcomic is an entirely different breed of blog-related web content. Instead of simply talking, the content is picture driven. For a webcomic people expect sketches, drawings, manga, comics, or daily 4 frames.
The web setup for such a graphic intensive content is more complex than what Blogger or LiveJournal usually offers. For one, you need to control your own hosting space because of the picture storage issue. You also need at the very least a simple way to upload and archive your pictures. There is also the issue of feed back, comments, news announcements. Almost all the Webcomic relies on php, which is a flexible and powerful scripting language.
If you want to run Webcomic, first thing you need to find out is whether your host support php and mysql, most of the school and service do already. You could also download Apache and turn your computer into a server, but unless your computer is on 24/7 there will be times when people can't access your content. If you own Windows XP Professional, you can turn on the IIS function and make your PC a general webserver that way. Both Apache and IIS require your computer to be on for long periods of time though.
The best Webcomic script I have found so far is Walrus. The script is in php and requires version 4.0 of php or better. Php of course, is free, and you can find it here.
Here is an example webcomic site showing what Walrus can do, you can find more links to sites that is "powered by walrus" at the left of Walrus homepage.
Now you have 3 things so far:
Server space: Either school server space, internet provider server space, or using your own computer as server space.
Scripting Language: php
Site Template: Walrus
Now all you need is a content management system. A software that would help you make changes to the website and make a website easier to maintain. The best well known example is WordPress. WordPress is flexible and powerful but if you have little programming experience I would recommend boastMachine. Both of the Blogging Platform I mentioned require php and mysql.
Then again, if you are only going to upload a small quantity of pictures, Blogger is already perfect for that. However, if you are looking to do something like pennyarcade you would need all those things I mentioned so far.
I hope the guide is helpful in getting you started on your own webcomic.