Upgrade from Exchange 2007 to 2010

hi,
 
Just want to know that how someone actually did migration of exchange 2007 into exchange 2010 server. Any guideline would be much appreciated.

First you will install Exchange 2010 with same roles on separate machine and then upgrade exchange 2007 data into it. At last we will guide you to import the mail record in HC under exchange 2010 server.
You can find detail from this like http://technet.microsoft.com/en-us/exdeploy2010/default(EXCHG.140).aspx#Home