Time Limits for BrainWave Generator?

I'v never actually used it. How does a good start go? I'm sitting at my computer, Is there a time limit to get relaxed? ;)

Edit - Well it's kind of newby so I thought, why not post it here.

I find that it puts me into relaxation very quickly, although it takes longer to go deeper. But I can feel the effects of it within a minute, I'd say. I start to feel sleepy and calm, and then it gets deeper....

i just tried it and for me...it got me drowsy almost instantly and put me to sleep in about 5 minutes, usually it takes me fifteen minutes to get to sleep when im tired, i was wide awake when i used it...so just start listning to it.

It has worked in putting me into a relaxed state, its never induced any lucids for me though.