or is that Ride DMC? (sorry, couldn't help myself). Welcome to the Forums.
On your topic...
I don't do stretches before riding, but hand pain? Are we talking numbness, or sharp pains? I did a quick search, and found Sheldon Brown's Pain page
If the skin of your hands gets sore, cycling gloves can help a great deal. If you ride bare handed, sweat may make your hands slippery, and this can lead you to grip the bars too tightly.
Wrist pain is often casued by poor upper body posture.
It can also be caused by having the saddle angle too low in front: This tends to make you slide forward as you ride, and you wind up using your hands to push yourself back into position.
Numbness of the fingers is a potentially dangerous symptom, often related to carpal tunnel syndrome.
This is one of many problems which can result from bad upper body posture.
The Two Bump Problem
Like your bottom, the heel of your hand has two bumps, with a sort of valley between.
There are important nerves which run through this valley, and it is important to avoid excessive pressure here. One common cause of excess pressure on this "valley" is riding on the top corners of drop bars in such a way that the bar presses here.
As with saddles, the "two bump problem" can actually be exacerbated by excessive padding! If you use thick foam handlebar grips, and/or gloves with too much foam/gel padding, the "bumps" that are best able to carry weight will press through the foam, but the foam in the middle will press back at the valley. Thus, as with saddles, too much foam/gel can worsen the problem it was intended to correct!
Numbness can also be related to poor wrist positioning. Generally, the wrist should be held so that the hand is pretty much in line with the forearm. If your hand is bent upward from the forearm, the nerves can get pinched, causing numbness.
Another thing I'd suggest is going in for a bike fitting. Proper fitting, and aftermarket hand grips can improve your riding experience.
Hope this helps you ride more comfortably.