You start the trek by descending on a small path through the pine forest. You meet the main path before long and keep on descending until you reach the river and cross the sturdy wooden bridge over it. From here it is a good two to three hours climbing on a fairly steep path which switches back on itself many times as it rises up the side of the ridge on the top of which Tengboche monastery is located. The path can be quite uneven, dusty and rocky.
Make sure you rest as much as you need to on this climb and that you are carrying enough water. Once you have reached Tengboche, there are a number of places to eat and drink, though these are mostly outdoor eating areas which are quite exposed, so make sure you have a hat and gloves with you. The views of Everest and the surrounding peaks from here are spectacular on a clear day and you can see the route continuing on toward base camp.
The monastery itself is wonderful, and you can go inside it and watch the monks chanting. If you are feeling strong, you can carry on down the other side of the ridge for about 30 to 40 minutes on a shallowly descending path through a rhododendron forest to Devuche, where there are a few teahouses and a small nunnery in a very peaceful location. From Tengboche, you return the way you came, descending back down to the river and then climbing up through the pine forest to Tashinga.