The main airport is Northwest Arkansas Regional Airport (XNA), which is about a 30 minute drive north of town.  There is very little in the way of transportation options from the airport, so plan on either renting a car or having someone pick you up.  Be aware that the airport is in a very rural area (more cows and chickens than people), and the nearest services are at least 20 minutes away.

Northwest Arkansas Regional Airport (XNA) 

The main highway serving Fayetteville is I-540, which connects to I-40 at Fort Smith- about a hour's drive south.  I-540 also connects Fayetteville with the other major cities of Northwest Arkansas- Springdale, Rogers, and Bentonville- which are all within 45 minutes of each other.