I don't work at SHC but I have been a PCT for about 6 months elsewhere. CNA's perform basic patient care, such as transferring the patient, setting the patient up for meals, help feed the patient, help the patient with his bath, etc. PCT's are trained to do those things plus a few other things, for me that was inserting/dc'ing Foley catheters, sterile procedures (needed for the Foley catheter), dc'ing regular heplocked IV's, and taking 12-lead EKG's. I've heard of PCT's that are trained as phlebotomists, as well.
The pay is not exactly high, I started out with no experience at about $11/hr. It IS hard work and you have stay on your feet for 12hrs, I got a total of 45 minutes break (15 for breakfast, 30 for lunch) and I saw a lot of nasty things (my last day as a PCT a patient actually voided on my shoes and pants). But at the same time it is excellent experience when you want to become an RN. You get direct patient experience, and you see so many interesting things. In the end it is totally worth it for a while, I would just not recommend it as a career in itself.
Good luck! I hope you find the right program!