I hope that fin-in doesn't feel that he's being picked on, having seen his other postings, I am genuinely concerned that he's going to get himself into difficulty.
I can understand enthusiasm to get into the water, but please don't be impatient.
I refer to his posts on this topic....
http://www.scubaboard.com/showthread.php?t=132551
fin-in, you have made one very good decision, and that is to join this board, don't let impatience be your undoing, there's no room for impatience in diving, it will kill you.
The advice that people here give you, should be taken very seriously, I doubt that anyone would condone you diving uncertified. And pretty much everyone will tell you not to attempt it.
When you dive you are not in the natural environment for a human being, and simple mistakes, or lapses of concentration, hasty decisions, that may be trivial on land. Can be fatal at depth.
The benefits of getting certified are that you will be able to enjoy your dives, you will not enjoy a dive if things begin to go wrong.
Nobody is trying to belittle you or patronise you, and we don't want you to abandon scuba board with that thought in mind.
If you are truly passionate about diving, you should read everything you can get your hands on, expecially accident reports. I also recommend you check out this book...
http://www.amazon.com/gp/product/0060194626/102-7158171-5090569?v=glance&n=283155
Some things that can go wrong......
Haste to get in the water, and not adopting a routine buddy check system can lead to you diving in with your air supply switched off, missing kit, unsecured fasteners on cylinders, bcd's weight belts, missing fins, mask etc (I've forgotten my mask before, and I've also absent mindedly put my snorkel in my mouth instead of my reg when striding off a boat).
Failure to identify the differences between fresh water diving and sea diving can lead to you being incorrectly weighted, and lead to rapid ascent/descent problems.
Old unserviced equipment that appears to work ok on the surface can fail unexpectedly, and at the worst possible times, without backup systems and at depth, this can mean drowning or getting the bends.
There are unusual and unexpected currents in some of the most unlikely places, both on the surface and at depth, they can flow in any direction, including up and down, and they can carry you away faster than you can swim, they can also change suddenly and without warning, failure to understand and respect the topography of locations you choose to dive can have serious implications.
Penetrative Wreck diving comes with an added danger of entanglement, and dis-orientation, silt-outs etc.
I don't need to go on, as all of this information is scattered around this board, and in books on the subject, but practically all divers you meet certified somewhere.
I recently finished buying my equipment, some second hand some new, all the second hand items are presently with my LDS for servicing before I consider using them, and I don't intend to dive outside of supervised environment until I have a lot more experience.
Good luck with the hobby, give yourself the foundations you need to get everything you can to enjoy it more.