CHA has a great run down of dos and donts.. which I shall copy and paste below.
I recommend walking with a first aid kit and diclofenac (cataflam, voltaren, etc)
Dont forget lunch, snacks, water and gatorade/slut prunes.
SAFETY GUIDELINES
What to Bring and Wear
Avoid wearing jewelry whilst hiking. Earrings, bracelets and necklaces may become entangled in bushes or branches and this could prove painful.
Avoid wearing perfumes and colognes as these may attract the attention of unwanted insects e.g. wasps.
Wear comfortable loose fitting clothing; t- shirts & long track pants (nylon material) are preferred. The wearing of jeans is discouraged as they may restrict mobility particularly when wet.
If you must wear short pants please ensure that your socks extend beyond your ankles and cover as much of your leg under the knee. This is for protection from scrapes by bushes or insect bites. Ankle socks offer very limited protection.
Please bring along a comfortable change of clothing and shoes. (Leave in vehicle) Leave jewelry and other valuables behind. Secure cameras, cell phones, car remotes in a water tight bag.
Use footwear with good grips on sole, no open shoes, slippers nor sandals. The Merrell brand is recommended. Please do not pick up a shoe that you have not worn in a long time to come on a hike. It is liable to lose its sole because unknown to you it has become dry rot.
Persons who suffer with asthma are encouraged to walk with their medication and to inform a hike leader before the hike commences.
Pack only what you need for the duration of the hike (drinking water, sandwiches, medication, etc.). Use a back pack to keep hands free.
On the Trail
Please follow all instructions given by hike leaders.
If you are in doubt about your ability to complete the hike without problems, heed the advice of your hike leader. It is better to miss the hike than to encounter problems which may result in an unpleasant experience for you or your fellow hikers. The leader may exclude any person from a hike or request them to return to the start at his or her discretion.
Please avoid consuming alcohol before and of course during a hike since this will impair your motor skills and lead to unnecessary slips and falls and possibly injury. We also ask that you refrain from smoking since your joy may be someone else's sorrow and of course bush fire.
No illegal substances or weapons allowed. It is illegal to remove spent shells from the forest.
Whilst walking try to keep both hands free of items e.g. water bottles, cameras, etc. Especially when negotiating slippery, uneven trails, crossing streams or walking in rivers.
Please stay on the trail. Wandering off on your own could mean getting lost. Inform us if you need to stop.
The first and last person in the group/section is always a hike leader. Please do not walk ahead of the first hike leader. If at any time while on the trail you are uncertain about which direction you should take, stand your ground, wait for a hike leader. The last person will always be a hike leader.
Do not hike alone, walk a short distance behind the hiker in front.
Avoid shaking bushes and making excessive noises.
On approaching an intersection/junction on the trail, one direction/s will be blocked by cut leaves/branches. Please use the unobstructed trail.
Pass over fallen logs, if you must go under, survey the area then proceed with caution.
Do not touch or eat any fruit or plant that is unknown to you.
Hike leaders have first-aid kits. Please ask if you need assistance.
Do not go into water until you are advised by a hike leader that it is safe to do so. Then enter feet first.
Preserve the ecosystem. Please do not litter. Take back garbage with you.
Happy Hiking. A positive mental attitude will take you a long way.