Alright...So you want to hike a long distance trail (or maybe just a bunch of short distance trails). After the first 15 or 20 miles, you're going to realize that the tennis shoes you bought at Wal-Mart or Payless just won't cut it. Don't get me wrong, these shoes have their place (for some of us anyway--Vin won't go near them, but Gwen can't pass up $10 tennis shoes that last 3 years at her desk job), but that place is not on the trail. You're going to need something durable that fits extremely well and just plain feels good.
First of all, if you're going to have good shoes to hike in, you have to understand what you're going to put these shoes through. Some of us hike through flat, dry, desert land I guess, but most trails aren't like that. You're likely to have to walk through mud and water, you will probably spend a lot of time walking either uphill or down hill, and you will be in these shoes for hours at a time. You should keep all this in mind when you're shopping for shoes.
The Right Size
Finding shoes that are the right size can be a bit tricky. The situation is only exasperated if the outdoor store employees don't know the first thing about fitting hiking shoes, but aren't willing to tell you that. First things first...any employee who lets you try on hiking shoes without hiking socks, measures your foot only while sitting, or lets you buy shoes after only standing in them or taking just a few steps should not be trusted. There are a lot of those employees out there (don't get me wrong, there are also some very knowledgeable ones, just not very many), so it's important to know how to fit your own shoes.
1. First you need to put on hiking socks. These are thicker than your regular socks and you need to know how that feels with your shoes. Any outdoor store worth buying from will have a basket of hiking socks or let you take some off the rack.
2. Now measure your foot. It is important to measure your foot standing up--after all, you will be standing in these shoes all day. When you stand your foot flatens a bit and this can affect size quite a bit in some people. Use the little metal foot sizer in the store--make sure your heel is all the way against the back, and see where your toe is--this is your size. But Wait!! Don't go running for the shoes yet. You also need to get a heel to ball measurement. In hiking boots, this is really more important than the overall size. For instance, Gwen's foot measures a 10.5, but her heel to ball puts her foot at a size 11. When Gwen tries to wear a size 10.5, the arch on the shoe does not match up well with her foot and causes her much pain. An extra half size of space in the toe box is not a bad thing at all, so she wears an 11. The last thing you need to pay attention to when measuring is the width of your foot.
3. Now that you know the size you need, it's time to pick a shoe so you can ask to try it on. Are you interested in weight? Try some of the low top trail runners (Lowa and Vasque make some of these). Do you have bad ankles? Plan on boots, or wrapping your ankle(s). A note here, if you plan on that, wear the ankle brace while you try on the shoes. Check to see if the shoes are lined with Gortex--this keeps them dry. Look at the way they lace up--will you be able to lace them with cold, numb fingers? Check out the soles too--are they going to work on the terrain you plan to hike on? Don't be afraid to ask the salesperson to get you ten pairs of shoes, or more. They're paid to do it, and if you ever feel pressured to buy, you should leave. It's better to try on a ton of shoes than to find out your first day on the trail that you bought the wrong ones.
4. Now that the nice salesperson has brought you those shoes, put them on, lace them up tight and see what you think. It you hate them while you're sitting there, there's no point in going any further, take them off and move on. Stand up and make sure your toes don't touch the end of the shoe. Still good? Walk around the shoe section. Ask the sales person where the ramp is. No ramp? leave. Once you find the ramp, stand on it facing uphill, then stand on it facing downhill. your foot should not slide around more than a half an inch or so, and your toes should not ever touch the end of the shoe. take a few steps downhill. Really slam your foot down to try and simulate 3 miles of down hill walking. If your toes still don't touch, you're pretty good. When your walking, your heel should not move more than half an inch. Are the shoes too wide? Is there too much volume? (This is the height of the shoe--from sole to laces). Volume can be fixed with new footbeds, so don't automatically throw out a shoe on this criteria. Found a shoe you like? Good, keep them on, head over to the pack department and get a pack off the rack. Load it up with about 30-40 pounds of weight (most outdoor stores have sand bags), sling it on your back, and walk around the store looking at whatever else you're interested in for thirty minutes or so. Keep in mind that you will have to break in the shoes, so they won't be super comfy, but your feet shouldn't really be hurting. Pay attention to small pressure spots or places that might rub a blister. Repeat as many times as is necessary to find shoes that are good. This is a decision you definitely DO NOT want to rush.
Now that you've found shoes you like, you'll need to break them in. Wear them for short spurts of time. Try wearing them at the house first, so that you can maybe return them if you decide you don't like them after all (REI is pretty good about returns). Breaking in shoes can hurt and can be a lot of work, so you don't want to do it more often than you have to. So you need to take care of your shoes. Wash the mud and dirt off of them when you can. Waterproof them with a good waterproofing agent, such as Nikwax (use the formula appropriate for the material your shoes are made from), that waterproofs while allowing the fabric to still breathe. Many people recommend putting a small amount of superglue on all of the threads on the outside of your shoes. This keeps them from breaking, and if they do break, it keeps the rest of them from unraveling. This seems to work well, but it is easy to go through four or five tubes of superglue. This is a small investment if it makes $150 hiking boots last an extra year or two.