Kathy....first please forgive me for not resizing the photo before putting it in my post....just grabbed one to show you how to do it from photobucket.
How to put a picture in your post from photobucket:
1) click on the image button above while in posting mode...it is the third green button from the right...it will put two brackets with "img" in both brackets on your post (you will see your cursor in between the brackets.
2)go to the picture you want to insert on photobucket and click (left click) on the "Direct" link in the "Share Links" box. It will say briefly that it copied the link
3) Now come back to your post and paste that link in between the img brackets where your cursor is.
4) If you want to also post wording / text into your post, make sure you have done that before or after the "img" brackets or the text will will mess up the link and your picture won't post.
For uploading any pictures from your computer you would do it the way Sheri said with the upload attachment. For inserting any pictures from the web such as photobucket...you would use the (img) insert image button and then insert the link.
I hope that helps you.