Could someone suggest a site for beginners?

Please compare some brokers and banks before you register yourr Demat account. Compare the broking charges and also thier customer service. Dont go by Big Names.
For Opening Demat Account you will need:
PAN Card, Address Proof, Bank Cheque, 2 Photographs

You can read articles and news on various sites dealing with share market of india. like:
www.moneycontrol.com
www.capitalmarket.com
www.sharekhan.com
www.paisabuilder.com

You will get share market theory knowledge on websites:
www.bseindia.com
www.nseindia.com

Also, make it habit of watching reviews on CNBC and NDTV.

You can accumulate all that knowledge only bit by bit. Don't worry though, if you have the passion to dig in deeper, you can cut short the learning curve by benefiting much from the experience of others, and by making your own, hopefully small, mistakes! Consider adopting all of these mechanisms below, to get more knowledgeable, slowly.

Option Tips  |  Currency Tips

Hi, It is really very good that you are going to start trading you can take a free stock and Forex Tips from any good advisory firm..it is easy way to start trading and analysis market. One good site here I am mentioning is www.trifidresearch.com    here you can find daily market updates and Stock Tips.