If you decide to drive or ride yourself, from Chiang Mai to Pai take highway 107 north through Mae Rim and turn left at Mae Malai onto "highway" 1095 to Pai (and eventually Maehongson). Pai is 134 km from Chiang Mai but this scenic mountain route will take at least three hours.
Local Bus from Chiang Mai to Pai leaves the Arcade Bus Station, five trips during a day (07:00, 08:30, 10:30, 12:30, 16:00). The trip takes about 4 hours and there is a comfort stop at the small half way village of Mae Sae (very good Northern sausages and traditional chicken curry noodle soup available as well as other necessities food water toilets et cetera). Bus trip costs approximately 80 Baht.
Minibuses and Small passenger trucks (song taew) carrying a dozen people also leaves from the bus station as often as there are sufficient passengers or full paying passenger. (cost of private hire is approximately 1200 or share for approximately 150 Baht). The rear seats approximately 10 people and is open air. The view and wind in your face is pleasant, but not the occasional exhaust fumes.
Drive yourself, plenty of car rental companies in Chiang Mai (e-mail us for recommendations). Small four wheel drive available but not necessary. The drive is pleasant. The road is narrow, winding and very steep in places. Recommend experienced drivers only. Secure parking at the resort. Last time we enquired rates varied from 800 to 1200 Baht a day. Bike (motor or push). Hire a motor bike in Chiang Mai or peddle your own mountain bike along the quiet and scenic road to Pai.