Ok, hopefully I can beat Minnflyer to doing this!

Step 1. Click the "Post Reply" button that is located below the last post in a thread.
Step 2. This will bring up a new dialog box similar to the "Fast Reply" box you are used to, with the exception of there being a "Click here to upload!" link that you can use. Click on this.
Step 3. This will bring up a file upload box. This will give you the opportunity to upload up to 12 pictures at a time. Click on the first "Browse" button.
Step 4. Use the Navigation box to browse to where the file that you want to upload is located on your computer. Once you have selected the file then click on the "Open" button.
Step 5. This should fill in the file name in the first line of the upload dialog box. You can use more of the upload lines to select more pictures if you want to upload more than one. Once you have selected all of the files that you want to upload then click the "Ok" button at the bottom other dialog box.
Step 6. Wait until you see the "File Uploaded Successfully" screen to appear, then click "Ok" to close that dialog box.
Step 7. Finally click the "Ok" button to upload your post and the pictures to RCU.
I hope this helps
Ken