There are two security stations, both bag check and metal detectors by the monorail. One side takes you to the escalators and the other side to the elevator. Security will guide you to the elevator. If you are walking, there is security right after you cross the street.
I can confirm what FFMickey said, that the monorail resorts have security and baggage check area before entering the monorail. I believe that I remember they checked my bag and wheelchair at the Contemporary Resort before taking the elevator to get on the Contemporary Resort to head to the Magic Kingdom. I didn't use the escalator like the other guests. After arriving at the Magic Kingdom I did not have to have my bags checked again, and I was guided to the MK gate entrances.
I also used the sidewalk from the Contemporary Resort to MK. There is a security and baggage check area on the sidewalk after you cross the street. They have a little tent set up, etc.
I also used the Disney Bus system to the Magic Kingdom and these group of guests enters the security and baggage check area before reaching the MK gates.
I also used the Disney Ferry Boat and monorail from TTC to MK and these group of guests enters the security and baggage check area before reaching the MK gates.
I also used the large Disney boat from Fort Wilderness Campground and Wilderness Lodge Resort and they had separate security and baggage check area at the entrance to the large/small boat dock with a small tent.
The small boats that leave the Poly and Grand Floridian resorts. They have a smaller boat dock near the monorail entrance.
They moved the MK security check from what you might remember before now. I remember leaving the Disney bus at MK and walking past the Disney Ferry Boat exit. Now they have moved the MK security and baggage check area just past this area.
I remember I used to walk down the hill toward the large/small boat dock and turning up the center and deciding between two security and baggage checkpoints. They still have the no bag area to the right at the new security and baggage check area. And to the further right is where people exit the MK park with security personnel directing newbies exiting MK to the bus or coming from the bus to head to the left to the security checkpoint if coming from the Disney Buses from the resorts.
The other monorail resorts the Polynesian Resort and the Grand Floridian Resort also had security and baggage check area.
Boy that was a mouth full.
Please correct me if I misstated anything.