@notareal said:
Worth to read http://www.sketchupartists.org/tutorials/sketchup-and-kerkythea/sketchup-and-kerkythea-fast-start-4architects/
and naturally classic KT tutorials master list http://www.kerkythea.net/forum/viewtopic.php?f=16&t=5720 (probably you find most answers to your question in the topic)
Thanks very much notareal! Every little bit helps.