Um, I've actually heard that creatine is pretty much the ONLY 'bodybuilding' supplement that has consistent positive correlation in clinical studies (it works!), has pretty much NO risks, and is pretty darned cheap (all things considering).
Creatine is an organic acid that occurs naturally in our bodies, and there are no risks associated with using it at recommended dosages because your body will naturally regulate your levels to get rid of any excess. Your cells use something called ATP (adenosine triphosphate) for energy; creatine effectively helps 'buffer' the 'byproducts' in order to have faster access to more ATP. It helps with endurance and force production; so you can work out harder and longer. And yes, it also causes your cells to swell, but this is actually a good thing! It helps all the good bits move around the cell easier, and also helps the cell eliminate the 'nasties' faster.
It used to be recommended to go through a 'loading' phase in order to help 'fill' your cells to the max level of creatine before 'maintaining'. But the general consensus these days tends to be that more than 5-7g a day isn't necessary - so you can start taking a tsp a day, that's all you need. There is SOME risk of water retention, which has already been mentioned, but the effects tend to seem exaggerated subjectively; that is to say, objectively, you're not likely retaining more than 1/2-3lbs or so extra. The trade off for the ability to work out harder and recover faster tends to outweigh the 'swelling'.
The kidney issue has to do with creatinine; excess creatine is turned INTO creatinine in the kidneys and then eliminated, under normal circumstances. However, in individuals who are experiencing kidney failure, creatinine can start to build up. If you're supplementing with TOO much creatine, there is also a higher level of creatinine (which is associated with kidney failure), and could cause a false positive in testing. There is, however, no correlation between creatine CAUSING kidney failure; so supplementing with it might make a kidney issue show up faster, but as far as I know, it won't damage anything in healthy adults at recommended dosages (ie. 5g, or 1tsp a day). It's even proven safe during pregnancy!
The only reason to avoid creatine is if you are allergic (which is rare, but can happen) which can sometimes result in symptoms similar to asthma. Oh shoot, no, sorry: you also want to pay attention to drug interaction; if you take any prescription medication, make sure that creatine won't interfere with it!
Ironically, some of the most recent studies actually show that women might gain MORE benefits from creatine supplements than men do. There is also some evidence that fewer women experience the 'swelling' from creatine loading as well. It's not just for guys, and it can definitely help you maintain peak performance during physical activity.
Don't bother with any of the isolates, either; just go for the bog-standard creatine monohydrate. All the fancier (and more expensive) options show the exact same results as the monohydrate, plus most studies still use monohydrate so it's the most likely to be guaranteed safe.
As for your muscle soreness; I feel your pain! Creatine probably won't help much after the fact, but if you take it on a regular basis it's supposed to have a bit of preventative power for after-workout soreness (which is also sometimes called DOMS, or Delayed Onset Muscle Soreness, if you're curious =P). The soreness from new movements and stresses can absolutely suck; I recommend trying an arnica balm directly after activity. Also, if you can bear to try, alternate hot and cold in the shower several times - if nothing else, this helps increase circulation, which is rarely a bad thing. But there are pretty much no proven cures or treatments for DOMS. Unfortunately, we will have to continue to embrace the suck.
I'm NOT a medical professional, dietitian, or even a fitness professional; I just read too much. :P But please continue to do your own research, and make your own conclusions; and ask your doctor if you have any concerns, or before starting new workouts. (y'know, the normal disclaimer stuff
I often reference a great site that summarizes information about loads of different supplements: examine .com
'Hope this helps!