SIGfiend:
Pictures work better than words.
www.corneredcat.com/Basics/grip.aspx
www.corneredcat.com/Basics/stance.aspx
If you're practicing for target shooting, stand in the most comfortable & relaxed manner you can and keep the sights aligned with the target while you pull the trigger.
If you're practicing for self-defense shooting, choose a stance that keeps your weight centered on the balls of your feet (like a boxer or a martial artist), with the gun held firmly enough that if someone grabs for it at close distances you'll have a fighting chance of holding onto it.
There's a huge controversy about elbows locked vs elbows unlocked in isosceles. Massad Ayoob's "Stressfire" technique is a pretty good example of the elbows-locked school of thought. Elbows locked allows the recoil to travel through your skeletal system and be passively absorbed through and dispersed by your entire body. It also tends to be more repeatable under extreme stress and it definitely is more repeatable when the lighting conditions are less than ideal.
Elbows-unlocked is taught by many IPSC and IDPA competition shooters, who find that it is somewhat easier to get good hits while moving with the elbows unlocked. With the elbows unlocked, recoil is controlled using the upper-body muscles rather than the skeletal system; some of these guys advocate relaxing the muscles and allowing the gun to fully recoil and settle back down on its own - advice that works very, very well with softer loads and less well with more powerful loads if you need to fire a second shot in a hurry.
Again, both the elbows-locked vs elbows-unlocked discussions above deal with the "isosceles" stance (pictures on the second link above). In both cases, the arms are "straight," but in the former case they're a bit straighter than the latter.
If instead you choose to go with the "Weaver" stance, it is proper to leave the elbows unlocked, and you can thus bring the gun a bit closer to your body with no ill effects provided you are using the push-pull technique (push out with the gun hand, pull back with the non-gun hand at the same time). Recoil is controlled using upper-body muscles.
Hope that helps!
pax