Flora and fauna
Bus from Otavalo to Quiroga (20 min, $0.30). In Quiroga you try to find people to share a taxi to go to the laguna (20 min, $4).
Fees and permits
Free. The park is open from 08:00 to 16:00 every day. Camping is prohibited and no permits can be obtained. However, along the highway that goes from Quiroga south, there are several spots where you can get on and off the trail without passing the official entrance of the park.
Take the outstanding hike around the lagoon 4½ hours with some time to stop. The trail is very clearly marked and the path is well prepared. Can be done counterclockwise (as indicated) or clockwise. In either case the trail starts and ends at the visitor center. The clockwise start is across from the visitor center where a sign says "Do not enter!" When going counterclockwise, you get to a rain shelter after about an hour. When going clockwise you are getting to the marked Quebrada Vicundos after about an hour and a half.
Just after sunrise (06:00) you might get spectacular views of Cayambe's white peak, and the Cotacachi. However, to do the hike at that hour you need to sneak into the park somehow.
There are rain shelters very high up. There are quite exposed and are not suitable for camping, which is prohibited.
There is a boat, $1.25 per person, but it rarely runs on weekdays as there aren't really that many tourists. You can of course pay for all the seats, or go on the weekend if you want to do this for sure.
A couple of vendors outside the main "La Muelle" complex.
Expensive but quality restaurant at La Muelle ($7 entrees and $1.2 for a beer). There is another restaurant called El Mirador up the hill.
Camping is prohibited in the entire park.