I always just open up two web browser pages at the same time. On one, I'm signed into RC, on the other, I'm signed into photobucket...then:
copy the image tag from photobucket
Go to RC reply box, click to get cursor in box, right click and choose paste
Hit space bar twice (don't hit "send reply" or enter or whatever, just leave it there)
Go back to photobucket, copy the image tag for the next picture you want to paste
Go back to RC, click to make sure the cursor is a couple lines below your first image tag
Right click and chose paste again
When you're done, chose "Preview Reply" to see if it looks like you want it to. If it does, then chose "Submit Reply". This is the simplest way I can describe to do this that doesn't involve all this ctrl this and ctrl that.
I would also encourage you to go into your pictures that you plan to post here on the photobucket page, click the edit tab above each picture, then go in and chose to resize the picture. They have a resize that is most compatible with posting on boards like this that is a 640x480 I believe. Choose it to edit the pic to that size, then it's not monstrous on here.