I use a program called photobucket.com and download my pictures on to that website and then I just copy and paste them Img into my post.....hope that helps.....good luck!
You can also go to uploads in the blue task bar at the top of each BYC page. It will take you to a page that allows you to choose to resize your pic for whatever purpose you will be using it for. Don't forget to check that box before you upload it!
Then browse for the pic you want to upload. Then click submit.
Once you have it uploaded, it will show on your uploads page, along with a thumbnails URL and a full-sized URL.
Right click on the actual URL bar of whichever size you want.
Choose "copy" and then go to where you are writing your post.
Right click on "paste" and the URL for the pic will appear.