What you get depends on what you already have and what you are willing to spend.
First, make sure that you have have a good running kit as your base -- good shoes, running socks, shorts, shirts, and, for the female runners, support undergarments (obviously, I can't make recommendations about this but check Runner's World for reviews). You don't have to spend a lot of money on the socks, shorts, and shirts -- I like Target's shorts and shirts and they're imminently affordable at $12-$15 each. For socks, my favourites are Balega Trail (made in S Africa) and WrightSocks' Running socks (double-layer). Socks always seem a bit pricey -- I seem to spend $6-$9 a pair -- but well worth it. Don't run in all cotton socks unless you have this thing about wanting blisters. Personally, I also want a watch to track my runs. I don't have anything fancy -- I use a Timex Ironman Marathon watch that tracks 100 laps (it uses 2 laps if I'm just tracking the total time of my run and not tracking intervals) and it doubles as my all-the-time watch. If you run during the sunny times of day, a good pair of sunglasses and a running cap are pretty essential -- protect your eyes!
If you have the basic kit, then add some safety gear. Get something that identifies who you are and contains emergency contact information. If you are involved in a running accident and can't communicate, this may well save your life. Personally, I use a Road ID wrist band with the interactive ID plate and wear it on every run, day or night. (Note: if you purchase something from Road ID after clicking on that link, I do benefit in some small way -- a discount or something.)
If you run in the dark (or at dawn or dusk), then get some good safety gear. Again, you don't have to buy expensive stuff, you just want to be clearly visible by drivers. A reflective vest would be my first purchase -- you should be able to get a good one for less than $15. A light is also a good idea both for safety and for seeing the road/trail. I have a clip-on blue Firefly Nova from Road ID and set it to blink. It goes on my Road ID wrist band. I also bought a 3-light LED clip-on headlamp from Wal-Mart that clips onto the bill of my running cap. I'm not interested in getting hit while I run!
Then, if you run in cool or cold weather or in wind/rain, add gear for that. How much you need to wear is very individual. Over the past 7 years, I've worked out what to wear based on the temperature:
- >/=50°: shorts and short-sleeved shirt
- 40°-49°: shorts and long-sleeved shirt (my favourite is a Brooks, bright green/yellow half-zip), light gloves in the low 40°'s
- 32°-39°: shorts, short-sleeved shirt, light sweatshirt/vest, light gloves, running cap (ears uncovered)
- 26°-31°: light wind pants over shorts, long-sleeved shirt, light sweatshirt, gloves, running cap
- 20°-25°: same as 26°-31° but I'll wear a light fleece instead of the sweatshirt and substitute a stocking cap for the running cap so that I can cover my ears. If I have them, then a pair of less breathable shoes made for inclement weather.
- <20°: running tights under either the shorts or the wind pants, heavier fleece or sweatshirt under the light fleece, heavier gloves, 2 pair of socks. The one time I've run in less 10° (it was 5°), I overdressed because I was afraid of the cold.
Once you have that gear and want more, then is when I would start looking at fancy gear. Sometimes the higher priced shorts and shirts really are more comfortable and better than the Target/Champion level of kit. The Nike+ iPod Sport Kit seems to be a good, inexpensive (if you already have a compatible iPod) device for tracking your runs. If you want something that gives you more information, then a Garmin 405 (expensive) is really nice. Add a heart-rate monitor if you'll actually use it (I just do a quick finger-on-the-pulse check at the end of my run). I don't listen to music while I run but that's because most of my runs are on the roads and I want to be able to hear what's going on around me. But, if you run on trails or a treadmill or maybe even on sidewalks, then another piece of gear would be an iPod (or, shudder, other MP3 player -- recognize my bias?). I can't stand Apple's ear buds so I would also get a set of sweat/water-resistant sports head phones -- my preference are the in-the-ear kind, not buds. The iPod Shuffle is a $50 splurge and adds almost no weight to your gear. For the running parents (Amanda), a jogging stroller lets you share the joy of running with your child and adds some Umph! to your run.
If you're doing long runs, then get hydration gear. Carrying a Dasani water bottle is fine but can get tiring. I have a simple Fuel Belt Sahara 22 oz bottle with a handstrap. Having the handstrap means that I can actually let go of the bottle to relax my hands. I also have a Nathan waist pack -- it does bounce a bit and that and the weight on the back of my waist take some getting used to but it's nice for long runs since I don't have to hold it. A lot of folks like the 2 and 4-bottle waist belts from either Fuel Belt or Nathan or other suppliers.
So, Amanda, those are my suggestions. Treat yourself to some nice gear and enjoy your running even more.
Run well, y'all,