There are tutorials in the FAQs at the top of Forum Technical Support that discuss reducing pictures. Additionally, I have a standing offer to resize pictures for members. (Send me a PM.)
Save the resized picture on your computer, located where you can find it.
Uploading the picture.
To display a picture in your signature, you must upload it to a forum server. That is done on your preferences page.
(The pictures in the tutorial were made using the RV.Net portal. The same steps are used for all portals.)
Click on the "My Forums" link.
Click on the "My Preferences" link.
Click on the Browse button
A standard Open dialog box will be presented. Find the picture on your computer and open it.
Scroll to the bottom of the preferences page and click on the Submit Changes button.
I'm not sure what problem I had, but it would not let me upload a photo to my signature. I double checked everything and it kept giving me an error. I changed the name of the file to a longer word with no Cap letter and it worked the first time.
Here are the specs of the file that would not upload:
Sig.jpg
20Kb
305x98 pixels
-Nightmare
2006 Chevy 2500HD Crew Cab 4x4 "Standard" Bed
-Duramax LBZ / Allison 6 Speed Auto
-PacBrake Airbags, Nitto Terra Grapplers
-Reese 18k Signature Slider
-Prodigy Brake Controller