step 1: get an account at a photo uploading site to upload photos. The most popular/free/easiest one is called "photobuckets" their website is below:

http://photobucket.com/register.php?link=topmenu

the above link will take you to the registered page.

just pick a user name, choose your password and click on next and follow the steps.

important thing at this stage is to write down your user name and password somewhere so you won't forget it.

*sidenote

photos and videos are memory hogs not only on your computer but also takes up a lot of bandwidth at forums such as this one. I think Doc has the photos in a limited size which is probably smaller than most would like to post. But he probably has to do it due to memory and/or bandwidth issues(this is where it gets costly for anyone that runs websites/servers and such)

so, photo hostings sites are created for that reason. They take photos that you have from your desktop, let you upload it, then let you share it anywhere you'd like by simply linking it to forums or blog or even ebay.

most of them, such as photobucket, know the limits that most websites prefer and will automatically shrink it down to the popular size/format so that you can link it without using too much bandwidth for either parties.

They may limit the amount and size of your photos per month. But unless you are going to post thousands of photos, you should be fine.

most people that upload their photos through their cameras will probably hit over 1 MB of memory, that is a lot to be sharing over the internet for it will slow everybody down. So what's good about these photo places are that they will shrink it down automatically for you.

Questions you may have are probably:

Q: uploading photos from my desktop? how do they do that, is it safe?

A: uploading photos from your desktop is done through a type of protocol (it used to be called FTP but there are more advanced stuff now) and you are simply sharing a "language" through binary codes with the hosting site. It is a bit more complicated that what I described but also that easy in a sense.
Nothing is ever "safe" but it is pretty safe since photobucket is a very reputable site