Resize Logo / Header ProJam Light
Design and Skin Customization
Are you making changes via the ACP > Skins > Skin Styles or are you making changes manually to the CSS file and then uploading it to your site?
Also, you may want to turn caching off while you work on your site, that way you see your changes right away.
Set your ACP > Global Config > General > Default Cache Seconds to 0 and then enable developer mode by going to your ACP > Developer > Developer Tools > Global Config and check the Run In Developer Mode check box.