Upgrade from SQL server 2005 32 bit std edition to 2008 R2 64 bit Enterprise edition

Hello,

We are planning to upgrade current SQLServer 2005 STD edition 32 bit to SQLServer 2008 R2 Enterprise 64 bit edition running on windows server 2008 R2 std edition.

please explain me some steps that i need to follow in order the upgrade process to go smoothly.

I have searched and read couple of blogs but did nt find any concrete info.

Thanks,
Bharat