Once you get the hang of things, JackieCat, you can personalize all of these aspects as well. Some people will create a list for their character catalog, describing their characters in a sentence or two and then linking said character to it's full profile for further reading to keep the catalog nice and concise and easy to navigate.
And as Goblin's said, you can have your character in as many threads as you can handle :)
Just keep track of your own character's individual time line (as in, which thread would happen first, etc). Most of us keep track of this in our character's profile.
And as goblin's said, any place you can store your photos to on-line will work! I tend to use deviant art, as I upload art there frequently. Most of these sites are free, so you don't have to worry about paying a fee or anything. Just note, the link to use in order to display your graphic is when you right click over an image, select the option "Copy Image URL" and paste that to make the coding call the image link.
Hope that helps in case you had any additional questions :)