Hi All - Hope I placed this in the right section.
I wanted to share several links I use constantly and hope some may find useful...

Firebug is a must have add-on for Mozilla Firefox. You can check for javascript, css errors, locate exact css entries you need to edit for custom css and so much more.

http://getfirebug.com/

If you do manual install / updates or need to upload custom logos. Also, when Addenster asks to turn on dev mode, unless you can edit directly on your server you need an ftp client to upload/download. An excellent free one is here:

http://filezilla-project.org/

For those who like to edit css, this link gives you 174+ colors, shades and their hex values. Also excellent css, html, php tutorials.

http://www.w3schools.com/html/html_colornames.asp

Hope these are of use to some!