Hi Donna,
Welcome! I am also fairly new to the board diagnosed end of May by my pulmonologist that gave me no real information, was officially diagnosed IIIA NSCLC on June 9, 2006.
I will start Chemo and Radiation soon so I cannot give you advice there but the PET scan was very similar to the CT scan except it took longer. The worst part was drinking the substance that reminded me of Maalox so they could better see my intestines abdomanol area.
Because I am Claustrophic, for my Brain MRI I took a Xanax one hour prior and kept my eyes closed for the hour test and only began to panic for the last five minutes. I didn't need any medicine for the PET scan.