Where can i take the bus from Tokyo to Osaka?

i heard the bus in a lot cheaper. Do i just go to like Tokyo station or something?

Thanks!

For the cheapest rates, you should compare the rates between companies. Few companies have English websites. The exception and my recommendation is Willer Travel:
http://willerexpress.com/

You should book online in advance.

Here are some more basics about overnight buses:
http://www.japan-guide.com/e/e2266.html

I drop in some ticket shops in Shinjuku.
They book and U can wait @ parking lot of Tokyo metro government locate on west side of Shinjuku.

In this season , the parking lot is quite cold !

Take care!