If your ultimate goal is to create games that you want to sell and redistribute, don't use GLUT (unless you absolutely HAVE to), and chances are you will not have any solid reasons to use it. SDL has much more to offer as a game dev then GLUT does. As it was already mentioned, GLUT is really old and is not actively maintained. SDL, however, is and is much more suitable for games as it was largely inspired for such usage.
In my experience, I have experienced better control and performance using SDL. GLUT is widely supported on nearly every OS, but implementing controls using GLUT is not feasible to say the least. I wrote a very simple game using GLUT on Windows once, and thought it worked fine for the most part, but when I ported it to other OSes, the controls were not nearly as smooth for what a game should have, because they were not suited for games (the keyboard timestamp feature will annoy you and everyone else who plays your game; also, the mouse input is not very smooth or accurate enough). SDL takes a bit more work to setup, but it's worth it.
Lastly, using GLUT, you are limited to legacy OpenGL, afaik. With SDL 2.0, you can easily create a context for the latest OpenGL version you want/need. This should be a deal breaker for GLUT in most cases alone.
Before I wrap up my response, I will give a small defense for GLUT. I actually have my latest game using GLUT atm. The reason why I chose GLUT (at the time at least) was because it was easy to setup, and my game in particular with it's mechanics were much easier to get up and running using GLUT. Another reason is that GLUT's borderless window was proven invaluable when deving and debugging on MacOSX. Lastly, I initially started writing my game on MacOSX, not knowing much of anything about OpenGL for Mac. GLUT just felt right at that moment, and it ultimately saved me much time, energy, frustration and needless hassle (there are some features in my game I never would have considered if I didn't use GLUT), but ultimately, using GLUT in a commercial game comes with a price. Since GLUT is not actively maintained, you are risking future compatibility with new OSes. The same old glut32.dll or GLUT.framework is not guaranteed to be working on the next Windows or MacOSX, respectively, due to possible removal of a specific API or something. That probably won't happen, but it can, and it's not worth the risk, IMO. When it's time for the release, I will likely switch to SDL to avoid that potential land mine.
My recommendation to you is to learn the basics of SDL 2.0. Don't bother with the deprecated SDL 1.x, and it's easy to get the two confused as many things have changed for the better, causing some functionality not to work (Example, if you want SDL 2.0 controller functionality, use this, not the legacy stuff because it won't work).
Don't worry about GLUT or legacy OpenGL. If your card/drivers support it, start learning OpenGL 4.1 or later.
Shogun.
