Or upload them to an album in your "garage" here on this site, then link directly from there.
Or use the manage attachements function below the post window and upload them from your harddrive, but be aware of the size. I use 600X800 as it's plenty large enough to show details but small enough to be accepted by most any website, and quick to upload.
There really shoud be a sticky or an FAQ on this topic, not only explaining how to do it but alos managements requirements on size and how many pics can be uploaded - it comes up on every forum I belong to.
If it's already here, I'm sorry I didn't find it to point the OP to....
EDIT: Well I should have done what I'm telling the OP to do, check the FAQ, all the instructions are there and easy to understand. My apologies to the management!