tripprep

First things first. Who is going and Where are you going?
Make a list of all involved with full names and phone numbers.

Obtain info on the area you are planning to visit.
Do a web search and find related sites. Use place names as key words. You will find someone with info.
Find sites with Chat rooms or Forums. Ask for tips and advice.
Know where gas, food and lodging is located and if any permits are required.

Obtain Maps- Get a good map book, Print online maps, or visit your local map store.
I recommend De LORME map books and USGS topo maps.

Decide what kind of gear is needed for the trip. Who will bring what and what if anyone backs out at the last minute. Have all bases covered.

Build your itinerary
List all the people in your group.
List in General order.The date, time, meeting place and departure point.
List any waypoints, planed camping areas, Any possible side trips that might be taken, and time of return.
Add a copy of any maps with a outline of planed routes of travel.
What is the Contingency plan?
What if your group gets separated or someone gets hurt?
Where will everyone meet up?
How long do you wait for them before getting help?
If someone gets hurt will one go for help, Where will that person go?
What is the local agency to contact incase of emergency?

Below is a reprint of a itinerary from a trip I took back in 1995.
Some names have been changed to protect the innocent.

Carrizo Gorge Hike. Three hikers Charlie,Peanut and DJ sleepy
Charlie and Peanut will be leaving Thursday night with Summer driving the Neon. We will pick up DJ Sleepy at his house and head east on I8 to Ocotillo. We will be dropped off in Fossil Canyon at our regular camp site. At first light we will break camp and head SW across open desert crossing at one point hwy S2 and intersecting the San Diego and Arizona Eastern Railway. Once on the tracks we will follow them west till reaching our first camping point at Dos Cabezas. Saturday morning we will continue on the tracks into Carrizo Gorge. We will spend the day hiking and exploring along the tracks. We will camp in or near one of the tunnels. Sunday we will continue along the tracks till we can see the Anza campground from there we will take the dirt road to Jacumba. We will call when ready for pickup late in the evening no later than 9:00PM.If something comes up and we need to leave and are not into the Canyon yet we will head east on the tracks till we reach Ocotillo. We will call for pickup.
If allready in the Canyon we will continue till reaching the Anza Campground for assistance. We will be carrying our expedition packs and all will be armed.
In case of emergency call San Diego Sheriffs Department. There is also a volunteer Fire Department in Ocotillo. Local Sheriff lives across from the 76 Station in Ocotillo.