Getting there: There are no railroads (and certainly no airports) heading to Yuanyang so your options basically consist of a bus or renting a little van and driver (honestly, it’s hard to think up an appropriate way to express 面包车). The bus departs from the bus station near the train station on Beijing rd, and as of this writing, there is a 7:30 PM and 8 PM as well as a few morning options.
Logistical note — I tend to get my tickets from the Camellia hotel travel office. They sell bus and train tickets, and the booking fee is super low (5 RMB). They speak standard Mandarin (can be a challenge in Kunming) and they do have a few staff that can speak at least basic English. I can’t call up the bus station and ask about schedule and ticket availability, but I can do that with Camellia. Obviously, you could buy your tickets at Kunming’s bus stations, but there are three, so if you’re not sure which one your bus of choice leaves from, it can be a pain. I have no reason to plug this place other than my satisfaction with their service. Give them a call, 0871-3166600.
On the Road: As of this writing, the bus first reaches the administrative seat of Yuanyang County which is in a township called Nansha 南沙. You can find nicer hotels here, and it may be simpler to arrange for guided tours of the terraces. If this is your final destination, however, I recommend taking the daytime busses. The night busses get here at about 4 AM.
I chose to stay on the bus until the bitter end, arriving at the old administrative seat of Yuanyang County, a village now known as Xinjie 新街. It takes about 9 hours to reach Yuanyang Xinjie, and they let you sleep in on the overnight bus once you arrive, since it’s the last stop on the Kunming-Yuanyang bus. While a bit more rustic than Nansha, it is also a lot more atmospheric. If you’re on the night bus and you want to go on to Xinjie, be cautious not to get off too early in Nansha. Yuanyang Xinjie is the last stop, and is VERY mountainous, when you perceive that you’re on a big mountain, you’ve arrived.
Room and Board: There are only a couple of hotels in this town, with the nicest doubles topping out around 200 RMB. (Dorm beds for 20 RMB in the Government Hotel, rooms are fine and clean but the shared bathrooms are stinky and the showers are completely awful). We didn’t see any hostel options although apparently there are some Hong Kong people running one somewhere. There is only one pseudo-coffee shop (think Nescafe) as of this writing. The local snack food/street food is amazing, but if you’re looking for a nice big dinner, you may be disappointed.
Once you’re there, you probably want to go back to bed for a few hours to recover from the bus. Never fear, rice terraces are best at sunset anyway, and given the UV in Yunnan province, you’re not missing out on many good photos at high noon (plus you’re avoiding skin cancer).
Finding the Terraces:
This is honestly the most challenging part of a trip to Yuanyang - actually getting out to the terraces themselves.
The first problem is that there don’t seem to be any published maps of the area available in Xinjie in any language. On the web, there are only a few hand drawn ones in Chinese. There was a rough but printed/official map on a sign in our hotel’s main lobby. I took a picture, photo-shopped it into plain black lines, translated, and voila! A bilingual map was born.

Feel free to grab it in full size from Flickr, but please comment or shoot me an email if you do, I’m just curious who is heading down. It’s not authoritative but it’s better than what you will find in Xinjie. (Do any guidebooks have maps of this place?? It’s not in the Lonely Planet.)
Second, you probably want to actually see the freaking fields. There are some right below town, but not much to look at. Our hotel had a big sign describing a tour bus that you can get on at 6:30 AM in Nansha and see a huge number of sites in a day. We didn’t do this for a number of reasons, including unwillingness to spend all day on a bus filled with Chinese tourists on an exacting schedule. On the other hand, if you really want to see ALL of these places and you only have one day, it may be a decent choice.
Alternatively, you can arrange to rent a van and driver or even a motorcycle cart for the day. Based on what I know about other areas of Yunnan, the van shouldn’t run more than 150 RMB/full day of everywhere you want to go in the area. Try to get them down to 100 RMB. The 3 wheeled car/cyclo type options will be cheaper, but also less comfortable and more limited in scope. It is also very easy to hike out and hitch around a bit. 5-10K rides back to town will run you about 10 RMB in the passing tourist vans, or more like 3-4 in passing motorcycle carts. Make friends with the local peasants and you may get a free ride (but it might not end where you expected).
Getting Away: Here is the bus map from Yuanyang Xinjie. (Click through to Flickr to expand it).

You can get very regular busses to Nansha (New Yuanyang - 45 min) and Jianshui (About 4 hrs, very pretty drive). A few busses head to Kunming direct each day. You can also bus on to Hekou (Vietnam Border) or Jinghong (Xishuangbanna) from here.
Further Info:
This is as good as it gets in English, from Maciej Tomczak on PhotoTramp. Great info on why to go there (no tourists) and how to take good photos once you are there.
I found this website on Nansha and this one on Xinjie (Chinese) to be pretty helpful, although it doesn’t say much more than I just did. Useful for the few links to other nearby cities as well. If you are into local street food and can handle spicy stuff, or if you like Chinese and South East Asian desserts, GO TO JIANSHUI on your way down or back (4 hr bus from Yuanyang or Kunming). The food was great, and there are cool Confucian museums and traditional courtyard houses and gardens.