Well there are many different ways to draw something to post, such as a character.

1) Rendering
You could render your character from a screenshot. This means tracing the lines of a character from a screenshot from a movie (eg. Balto) and colouring/editing parts to fit your own character's design.

2) Tablet + Drawing Programs (Photoshop, SAI, etc)
You can also use a tablet to draw your character into a program like Photoshop or Paint Tool SAI. Both of these programs cost money, but an example of a free one could be Gimp.

3) Traditional
Another way is to draw your character traditionally (that is, with pencils, paper, or any other medium you choose) and then scan it in, or take a photo. If you want you can even go over the lines with your mouse in a drawing program if you don't have a tablet and make it digital.

4) Linearts
You can also use linearts made by other people to colour your character. The lineart HAS to be a free-to-use lineart for you to colour it, so if you aren't sure check with the original artist.You can find some right here on AS, or maybe check DeviantArt to find some.

Hope this helps ^^

Please use the search before making new questions, this has been asked so many times before.