Guide to purchase from ebay.com :
1. make an account with a shipping forwarder like shopandship.com . they will give you a US and UK address of their warehouse that you can use as your delivery address.
2. make a paypal a/c with your indian credit card.
3. you must have an indian ebay a/c, preferably with a few positive feedbacks (they are not mandatory, but they help)
4. add address in 1. to your indian ebay a/c and then you can start bidding/buying from ebay US (ie, ebay.com)
5. buy only new items from won auctions or direct buys, pay from paypal (your indian credit card will get debited) and give the address in 1. (ie, your US delivery address) on the checkout page.
6. Seller will ship to that address, shipping forwarder will receive it and ship it to your indian address for a fee. they will clear customs for you and you've to pay for shipping+customs+tax to the delivery boy.