Safety Checklist

Shot Put

Inspect the surface of the ring for any protrusions or indentations. These can cause the athlete to loose their balance and potentially fall, causing injury
Make sure that the ring is swept and free of any grass, dirt or other material that may effect the traction of the competitors' shoes
Make sure that the yellow area is flagged off or otherwise partitioned so that non-competitors cannot wander into it
Make sure that the landing area will not create unusual bounces or ricochets.

see the note on divots below
don't allow anything foreign in the sector that may cause a bounce (i.e. markers)
large stones can be a problem as well, especially with the smaller shots (4K and under)

Divots should be filled in so that officials or workers will not twist an ankle, or trip and fall.

Consider having a meeting with parents of athletes (and the athletes) to explain your safety procedures and why throwing safety is important
Practice/warm-up with implements does not begin until the coach is present
Depending on the number of throwers and the number of implements, consider using "salvo throwing"

Assume that you have 5 implements and 10 throwers. Have the 1st 5 throwers each take a throw, then have the second five throwers retrieve them and takes their throws.
No one enters the red zone until all of the implements have been thrown.
Never allow athletes to throw anywhere other than into the landing sector.

When practice is over, all implements should be put away.
Have a set time for practice.
Never allow unsupervised practice. You may be liable for negligence if you allow the athlete to practice outside of direct supervision.

check with your school solicitor for more information
consider private liability insurance
organize a "throwing club" with USATF membership to provide an additional level of indemnity
understand how your state views the terms "negligence" and "reasonable care"

Coaches:

Identify the head official so that if problems arise, you know who to address
If you see a potentially hazardous situation, bring it to the attention of the head official IMMEDIATELY.

This is also true if a situation becomes hazardous during the course of competition.

Don't assume that the head official sees the potential hazard and has corrected it.
If the situation is not corrected, and you feel that there is potential for injury to your athlete or another athlete, seek out the head field judge and point out the hazard, and the fact that you have asked the chief judge to address it.
If not satisfied, make the tough call - do you want your athlete to continue with the potential for harm?
Document the hazard through a formal protest.

Officials:

When the circle is closed, place a cone in the center to indicate that the circle is not available for warm-up or practice
Don't allow unsafe footing conditions to occur. Keep the circle clean and free of debris.
If you need to sweep or clear it, do so at then end of a round, or at the request of a competitor.
If at all possible, ask meet management to do any mowing around the circle at least 2 days in advance of the competition, and to clear any grass clippings from the circle.
Do not allow warm-up throwing in any other area, unless that area is supervised by another official, coach or adult. Never allow athletes to warm-up in or near the impact area.
When possible, ask meet management to erect barriers or other physical obstructions to the impact area. This will go far in preventing others from straying into it.
Refer to the inspection routine guidelines above.

effective, fast and efficient way to keep a circle or runway clear of water, leaves, grass clippings, etc.

if the impact area is dirt, gravel or some other materials than grass, keeping it level will help to alleviate tray bounces of shots that hit other divots. Also, it can save the ankle of an official if the landing area is kept smooth and flat as much as possible.