Sd card complete details and about fat also

[Damomeera]

pls help me.
i wanna study about sd card.
it's internal drivers, firmwares etc.,.
and also i want to interface with pic.
i want complete details

 

[Artlav]

Off the top of the Google:
Card interfacing and so on - http://www.frank-zhao.com/cache/fat_sd.php , **broken link removed**
FAT for MCs - http://elm-chan.org/fsw/ff/00index_p.html

Should provide sufficient details to start playing with SD cards, more than that you'll have to ask specifics.