Pakse is the crossroads and administrative center of southern Laos. As crossroads go, it is a very relaxed and laid-back place. It is not packed with attractions but it is a pleasant city in which to pass a day or two. Being at the confluence of the Mekong and the Se Don rivers there are plenty of spots to enjoy a cool drink while taking in superb river views. Its geographical position as a center of commerce has been further boosted by the opening of the Lao-Japanese Bridge over the Mekong across which trundles an endless procession of trucks carrying goods from Thailand. This has increased trade and the modern part of town that adjoins it is a bustling area of markets, truck stops, and commerce. The old part of town (where the hotels and restaurants are) is far quieter. If you have limited time it makes sense to use Pakse as a base for day trips to Wat Phou, the Bolaven Plateau, and islands in the Mekong.
In terms of orientation pretty much everything you need is to be found on near Rd. 13 from the old French Bridge up to the roundabout next to the Champasak Palace Hotel.