So I've made a list of the park's staff from the novel, and there is a minimum of approx. 20 personnel on the island according to Ed Regis.

Control Room

1: Chief Engineer- John Arnold

2: Control Room Attendent (Employee whos ear is found by Lex)- Unknown

Security

3: Park Warden- Robert Muldoon

4: Guard (1st Floor Lobby)- Jimmy

5: Guard (2nd Floor Lab)- Unknown

Genetics Lab

6: Chief Geneticist- Henry Wu

7: Lab Technician (1)- Unknown

8: Lab Technician (2)- Unknown

9: Lab Technician (3)- Unknown

10: Lab Technician (4)- Unknown

Animal Care

11: Chief Veterinarian- Gerry Harding

12: Nursery Veterinarian- Kathy

Park Maintenance

13: Maintenance Worker (1)- Carlos

14: Maintenance Worker (2)- Ramon

15: Maintenance Worker (3)- Tican 1

16: Maintenance Worker (4)- Tican 2

17: Maintenance Worker (5)- Tican 3

Visitor Staff

18: Head of Public Relations (General Manager)- Ed Regis

19: Tour Guide (Female)- Unknown

20: Tour Guide (Male)- Unknown

21: Tour Guide (Male)- Unknown

Park Dining

22: Cafeteria Cook (1)- Unknown

23: Cafeteria Cook (2)- Unknown

24: Bungalow Cook- Maria

Sources of Personnel

After reading the book several times, I've attempted counting the personnel, and this is the most logical conclusion I've come to. Lex finds the ear of a worker on the floor of the Control Room near the end of the novel, but the rest of him is presumably eaten. There are two security guards on the island, one in the lobby of the Visitor Center, named Jimmy. He spots Nedry going to the garage. The other isn't named, but he is the one that reports back to Arnold when they're looking for Nedry. In the chapter "The Tour", Tim notes that there are four lab technicians. The only known maintenance personnel are Ramon and Carlos, but two "Tican workmen" go to the Safari Lodge when they find out the raptors are loose. A third nods to John Hammond when he is walking to his bungalow. That leaves five total maintenance personnel, two guards, and four lab technicians. When Grant is walking to the Land Cruisers, "Two blackmen in Safari uniforms opened the doors". These I've called Tour Guides (male). The female Tour Guide handed out pith helmets near the beginning of the tour. Finally, Maria is stated to be Hammond's Bungalows cook, and there are probably two cooks working in the Visitor Center Cafeteria.

Any thoughts? This is the closest I've gotten to naming the entire personnel, but if anyone finds any flaws or has any other thoughts, I'd like to know!