Hi Ashhoq,
If you want to migrate files to SharePoint Online, I'd like to provide you with a similar thread(see the information Mark Klinchin and Benjamin Niaulin provided):
http://community.office365.com/en-us/forums/154/p/71019/264913.aspx
Q: How do I archive files to free up cloud space?
A: You can download the files to the local hard drives and then delete the files from SharePoint sites.
Q: Is sharepoint content searchable with a ‘bing’ style search engine? Does this cost over and above the standard license price?
A: SharePoint public website content can be searchable with search engine. However, SharePoint Team site can't be searchable with search engine.
Q: Do I need to maintain Chinese Walls between sections of our business – can this be enforced by the system administrator?
A: No, you don't need.
For more information about how to start using SharePoint sites, SkyDrive Pro, and Newsfeed to share documents and ideas, please see:
Thanks,
Keats Ge