In every theme that I write I always put this snippet of code in my theme's init_custom.vm file.

## ---------- Logo ---------- ##
#if (($company.getLogoId() == 0) && $use_company_logo)
     #set ($site_logo = "${images_folder}/custom/logo.png")
     #set ($site_logo_height = 69) #set ($site_logo_width = 403)
#end 

Gist Link

What this snippet will do is display the site logo if one has been set, If a company logo has been set it will use that, if there isn't a company or site logo, then it uses the logo.jpg in the theme and displays it instead of the default liferay logo.

Please leave a comment below if this was helpful, thanks.

Bradley Wood
Woodbench Media
80W. Sierra Madre Blvd, #109
Sierra Madre, CA 91024

www.woodbenchmedia.com