At checkout page I selected checkout method as register. Now I completed billing information (it is included also register info). After going to next step meanwhile I'm checking in the admin panel to see customer information. But nothing is there. I know that the entire steps stored in quote object temp. After placing the order it will store as a permanent thing. But I want to store customer information permanently once I fill the billing information. Thanks in advance
There are two things to take into consideration here: customer will be saved once order is placed, not in the middle of the checkout process. If you still want to save the customer when billing is filled, you might want to create an observer. This is explained here: customer save before process checkout button click
Actually the address is already saved in quote table, you can use that is it fits your requirement. This is the table that gets it all saved.
In magento, the information that is saved during the checkout process is a quote and once the process is complete, an order is created from the quote.
Logically speaking, the person who requests a quote is not yet a customer so no customer account is created for this person, once the order process is complete the information is used to create a customer. So, you won't see any customer being created in the backend until the order is placed.
However, if you somehow want to access the information of a quote this is found in sales_flat_quote table and you can access it anytime to get the information you need.