This outlines the 25 minute pre-ride "safety session" or "advice clinic" which I give prior to GPC Novice and Century-Prep rides. (Yes, it can all be covered in 25 minutes if one is concise.) I posted this in hopes it may be useful to other ride leaders. But it's an outline only: If you don't already know the material, some of it won't make much sense.
(BIKING — MINDSPACE — WHY?)

SIMPLE BIKE CHECK

• Static:
  • Brakes — adjustment; not rubbing against sidewalls.
  • Cables (visual)
  • Bounce check — quickly reveals many problems — investigate any rattles.
  • Tires pumped
  • Quick visual tire check — for cuts, etc
  • Careful tire glass check (not right now, though)
  • Quick release — correct tightening
• Riding:
  • Derailer check (not right now, though)
• Anyone who fails — go see a co-leader for adjustments.

ELEMENTARY BIKE HANDLING

• Starting — the correct way. It checks your brakes, too.
• Relax your hands and body. Avoid "death grip".
• Arms bent. Hand positions. Thumb position!
• Power comes from thighs & glutes. Pedal in 'circles.'
  • Avoid upper body gyrations.
  • Trunk braces the legs.
  • Pedal in 'circles.'   How to tell and practice
• Steering: largely with your weight. The bike naturally goes straight when your weight is centered. (That's why riding no hands works). Internalize this ... it may save you a spill!
• Constantly scan the road surface for hazards: potholes, debris, glass.
• Looking back: Chin touches left shoulder (L.A.B. method). Neck stiffness/looseness.
• How to brake:
  • Evenly, but front does the work.
  • (Demonstrate front vs. rear, walking the bicycle)
  • For hard braking: weight back.
• Control your speed on downhill. Feathering & pumping brakes.
• Posting (demonstrate).
• Resources:
  • Bike handling classes, e.g., Mike Cox.

RIDING MULTIUSER PATHS

• Be courteous of peds, etc. You are the faster & heavier vehicle.
• Watch out for dogs, kids, baby-strollers, rollerskaters, etc.
• Pass on the left; call out and ring bell.
• Single up if the path is busy.
• Some have posted speed limits, e.g. 15mph.
• If stopping, pull off the path.
• Less challenging & less excercise than open road.

RIDING IN TRAFFIC

• Lots of novice bikers are afraid of riding in traffic. They shouldn't be. They simply haven't been educated.
• Share the road. This means:
  • Bikes & cars share the roads, often the same travel lanes.
  • Same roads, same laws.
  • Cooperate with drivers and they should cooperate with you. Eg: Let them pass when you can.
• Vehicular biking: Think like a vehicle; act like a vehicle. You'll be treated like a vehicle.
• Be just as alert to traffic & obstacles as if you're a car driver.
• Where to ride on the road? Lane positioning: done by speed:
  • To the right;
  • Not so far right you're in the doorzone / debris zone;
  • Not in the shoulder, unless it's very good quality.
  • Not on the sidewalk, unless under 18 (depends on municipality).
  • Not in right turn lanes when you're going straight.
• Be predictable. Don't weave. Act the way you'd want a car driver to act.
• Always observe lane markings, traffic lights, etc. Always ride with traffic.
• Intersections (done by destination): Always take the right-most lane that goes where you want.
  • Turning left: Use the left lane (or rightmost left-turn lane, if several).
  • Going straight through an intersection which has right-turn-only lanes: Where should you be?
  • Differences if entering a road from a bike path. Then what are you?
• Take the lane:
  • Always, when stopped in an intersection.
  • Whenever the lane is too narrow for safe sharing.
  • When safety otherwise dictates — e.g., moving same speed as auto traffic
  • But not unnecessarily.
• Summary: "Bicyclists fare best when they act and are treated as drivers of vehicles." —John Forester.
• Drive defensively, bike defensively.
• Common sense and common courtesy.
• Resources:
  • John S. Allen's Street Smarts. See the full text on-line.

RIDING IN A GROUP

• Great fun, but need to avoid problems.
• Ride a 'straight line'. Again, be predictable. Think of being in a freeway lane.
• When much traffic: ride single file, except when the group takes the lane (e.g., to turn left)
• Be alert to other bikers, ahead and behind.
• Bad things to do:
  • Quickly stop in front of someone.
  • Veer into someone's path.
• Don't follow too closely — but assume someone is following you too closely
• Don't pass on right — except if very safe and necessary; then call out. (Exceptions)
• Calling out:
  • "Car back" (single-up for cars to pass) (don't over-call this one)
  • "Car up" (narrow tricky roads only)
  • "Ped up" (if on the right)
  • "Slowing"   "Glass"   "Stopping"
• Hand signals
  • Left.   Right.   Slowing.   Stopping.
  • Point out hazards.
• Drafting, pacelining, and tight packs are advanced techniques. Not for novices.