the best place to start is get out there and do it!
take plenty of water, it is reccomended one litre for every hour you plan on being out there, this will decrease as your fitness increases, sip it regularly rather than stopping and skolling heaps in one go. museli bars are EXCELLENT low GI snacks, as is beef jerky/biltong, you have to watch what brand you get, and if you have a local biutcher that makes it i would reccomend you to it, many have a very high sodium content (that will dehydrate you) plus a lot of chemicals and preservatives. apples and bananas are good if you can carry them without squashing em. barley sugars can be taken, but usually only used in emergencies (ie if you're really tired at the end of the day but still have an hours hike to go) AVOID high fat foods, potato chips, candy, overly processed foods.
start small, find some well formed tracks in your area, and start doing a few hours once or twice a week, the more you do it the better you'll get, the longer you can go for etc, then you can feel more comfortable going out into the rough stuff, bush bashing, steep trails etc.
once you're out there for 4-5 hours you'll want to start taking lunchy food. sandwhiches and filled rolls are best. wholegrain bread is better than the floury dough crap white bread that everyone seems to eat. what you put on it is up to you, i like cold meats and cheese with tomato and lettuce, chicken and mayo.
pace yourself. dont start at the bottom of a mountain running, find a steady walking pace and stick to it, speeding up and slowing down messes with your body's metabolism.
SHOES. you WILL need GOOD shoes or boots. there is no shortcut for this, and they're not usually cheap. people who do it for a living pay upto 1000$ for a pair of boots. i would reccomend at a MINIMUM that you spend 150$ i paid 300 odd dollars and have had and used my boots for about 5 years now.
a rolled ankle is no joke, and blisters suck fun out of walking like paris hilton sucks the XXX out of XXX.
a good backpack is also a fantastic idea, ask someone at an outdorr rec shop. a bad one will give you sore shoulders, a purse or handbag will be the ruin of you.
ENJOY
