Just go through all the categories, like Sudhershana has said.
You will find Scooters, bikes, cars etc in the automobiles, refrigerators, televisions, Chimneys and more in the Home and similarly in the Electronics, Computers etc.
You can see lots and lots of products under the $ sign for which you can write reviews..
If you are the first person to write a review for a particular product you get 2 bonus points. You will also earn cash for the reviews. So go ahead and put in as much reviews as you can.
About the review contest, the product has not yet been announced. Please do wait for sometime. It will be announced in a day or two.
Editor - IRC
India Review Channel