So I always recommend two different microphones. Get a dynamic microphone and get a condenser microphone.
Dynamic Microphones
You can't go wrong with an SM 57. Some guys prefer this mic or that mic over the 57. That's fine, but the difference will be fairly subtle to a beginner. On guitars, I love my Royer R121 ribbon microphone which costs about 15x as much as a used SM 57. However, it sounds a little different. Not mindblowingly different. ...Just a little different. I have a feeling that something like the Sennheiser 409 would be a nice choice, too. However, you probably will pay more for one and sell it cheaper than you would a 57. Just get a 57 and be done with it. If your guitars suck with a 57 than more than likely the problem isn't going to be solved with a new microphone.
Condenser Microphones
For the beginning home recording guy on a shoestring budget, the MXL mics are great! Which one? Who cares? You won't know the difference anyway. Buy a $100 one and learn with it. Then when you buy a new mic you'll know the difference. This isn't something that can be demonstrated in an article or a forum.
I really like the MXL V69. It's the $300 tube mic. Just remember it has to warm up for 30 minutes before using it. This can cause problems when you are in a hurry. This is why I recommend getting one of the cheaper, $100 models. Then work your way up.
There are many other $100 condensers out there. Don't over think it. Just buy one so you can get busy recording. You can put more thought into purchasing future microphones. If you can get some bundle that includes a soundcard and a microphone pretty cheaply, do it and be done with it!
Conclusion
I don't mean to suggest that you shouldn't research your purchases. You should always plan ahead and know exactly what you are getting before you get it. However, I know of a lot of recording people who spend way too much time browsing the internet and not nearly enough time actually learning to use their home recording gear.
Home recording is a lot like sex. You learn by doing. Books, videos, and forums can give you tips, but it's up to you to get to the promised land.
Good luck with both!