If you find a link to a picture of the exact lock or the model number of the lock you are trying to pick it would be of great help when trying to answer your questions. A needle that has not been modified is not what I consider to be a lock picking tool and purchasing a set of lockpicks or making a set would be of great help to you. This set would be a great place to start
http://www.lockpicks.com/product.asp?0=204&1=217&3=270 but if you don't have that kind of money a smaller set will work just fine.
Also, do you have a key to this lock? If so make sure the lock works before trying to pick it. Flushing out the lock with some sort of spray teflon/silicone lubricant will more than likely help out alot if the plug does not move smothly when opening the lock with the key and it will more than likely make the lock easier to pick. It does not look as if you have read the MIT guide to lock picking (I am assuming this because if you had I would imagine that you would know what a plug is.) and reading it was what made it so many people on this site, including myself, were able to pick our first lock. The article on howstuffworks.com is also something I would recomend looking at because it has some animations of how a key works in a lock and this will help you to visualize what is going on.
MIT guide:
http://www.gregmiller.net/locks/mitguide/
How stuff works:
http://home.howstuffworks.com/lock-picking.htm