Join the Site
Join the site Luke, it is your destiny. Also it's the only way we can prevent spammers from using our site to advertise prada handbags.
Think up a Name
Got one? Type the name of your PC in the "Add a new page" box, in the sidebar.
Load the PC Template
Either the wiki will say something like "Dude McFighter" doesn't exist, and give you a link to click to edit the page, or it will send you to the edit page directly (it seems to behave unpredictably). The edit page looks like this:
In the shot above, I'm selecting a template from a pulldown menu called "PC Name". Find that menu and select that template. That will pre-populate the page with a nice little table for your stats, powers, hit points, etc.
Fill in the blanks
Then go ahead and fill in the table. Everywhere it says "stat", put your PC's Strength, Intelligence, etc. Where it says "your-user-name" put your wikidot user name. Where it says "a class" put down your PC's class. Ditto for experience points, gold, etc.
There's a line that says "Special". Here we tend to put things like "Magic-User Spells" if the PC has access to those, "Thief Skills" if he's got those, various languages spoken, and any other special abilities gained at char gen or during play (for example, some people have strange chaos mutations, some are undead, etc).
Then save the page. Your dude is created! But you're not quite done yet.
Tag your dude, dude
Then you need to click the "Tags" link at the bottom of the page and type in your campaign tag (usually "black-peaks" or "algol"), a class tag ("fighter", "magic-user", etc) and the tag "pc".
That will ensure that your PC appears on various automatically generated lists of PCs and campaign-related pages.
And now you're done!
Bonus points
If you experiment with the wiki syntax, you can figure out how to put in images and format lists of equipment and other notes on your PC. Have a look at some other PC pages, click their "options" link, and the "page source" link to see how it's done. If you get stuck, ask for help on the forums.