i put my ass on the seat, my hands on the handlebars, and my feet on the pedals. any questions?
this is one thing the internet is NOT good for, you need some hands on help. go to critical mass and ask someone to show you, hopefully they are friendly enough and willing to help someone ride a bike (i'm nice and friendly and willing to help people out, and i go to CM). other than that, bring some beer to the LBS and maybe they'll help.