Hi Lucaz22,
The lotion idea above is a very good one.
The cracks and grooves on your penis are there all the time it's just that when irritated they can appear more visable. It's your body's way of showing you something is up.
A common issue i see that can cause the head of the penis to appear as though it is cracking is not cleaning the penis properly after ejaculation. This can lead to a dry apperance on the glans that makes the tissue appear to cracked. Try to make sure you wash after masterbation and intercourse if your sexually active.
The apperance of a new vain could be your penis growing as your move further into the adventure that is puberty. If it is worrying your go get it checked by a doctor.
Most towns and cities have free sexual health clinics...best way to find one...google!
Although the problem might not be directly related to sex/masterbation, sexual health clinics (GU Clinic if in the UK) are the best place to go to get your penis given the all clear.
if you're worried, go see a doctor! Or try putting some non-scented organic lotion on it or neosporin. It could just be dry skin, the winter time really does a number on some peoples skin.