if you havnt installed anything yet then open your installer and install BSD subsystem first.
then once that is installed go back to springboard and let it reset. open installer again and install summerboard. then again reset the springbord and then you can go to installer and under themes summmerboard look at and pic out themes to install.
i must warn you! don't install anything on the phone until you have reserched it first. it will save you lots of trouble to do a lil reading before you start downloading things to your phone. good luck!