Absolutely you should contact professors ahead of time. I sent a short introductory paragraph, a sentence or two about my research interest, and I asked if they would be willing to correspond by email or phone. Of course I didn't hear from everyone, but I did get responses from 50-60% of the folks I emailed. On top of that, everyone with the exception of one school (Stanford), was willing to talk with me by phone. I asked for 10-15 minutes of their time, and almost every call resulted in a 30-45 min conversation because we got along so well.
Look you need to speak to these people in person. Sure you might match research interest wise, but if you don't get along talking would you really want to have this person as your mentor for 4 or 5 years? Calling gives you immediate information and you can rule out advisers pretty quickly from their tone/temperament alone. You can get a great sense of the program from how they talk about it and if you pay attention you can pick up on important buzzwords for each school. Trust me it works.
The faculty remember you. You can name drop in your statement of purpose, "speaking by phone with Dr. xxxx, I was able to gain a sense.." etc. Slip those buzzwords in. I promise they will remember you.
Yeah you can be scared but what is that going to get you? Nothing ventured is nothing gained. There is absolutely no advantage from not calling, but a huge advantage if you call/email and you connect. If you are new to this start with your bottom choice school so you can learn, hell call a school you aren't even interested in. It's a confidence builder.
And it works. I have 2 interviews, and I'm waiting on my 6 other schools... with fingers crossed.