You could use wood glue, it's really strong and I'm sure it would work great. Having built balsa kits and done a great deal of scratch building, I think my choice would be to use super glue. There's a company called Bob Smith Industries that sells a line of adhesives with different viscosities. Their super glues come in Thick, Medium, and Thin. The thin being like water. They also carry a super glue accelerator called instant you can get your pieces in place glue them, then spray with the accelerator and within seconds move onto your next piece. Speeds up the building process a lot. Good luck.
