Does anyone know this Scifi trilogy written in the 70's (or maybe 80's):  the main character is a young man who reads a how-to book about using the power of thought to travel to different dimensions.  At the beginning of the first book, he tries the technique in his room and it transports him to a different world where the rest of the three books takes place. I remember this series being somewhat funny and possibly written by popular author. 

Update:  I recently stumbled upon the series I was looking for...it is by Keith Laumer -- his Lafayette O'Leary series.   (It seems this series wasn't familiar to anyone else, but I decided to share this just in case someone was curious.)