From Pakse, get a bus to Salavan (leaves from the Southern Bus Station aka 8km Bus Station at 07:30/09:00/10:45/12:00/14:30/16:00) and asked to be dropped off at the road for Tad Lo (30,000 kips). From the drop-off point after the bridge, it's about 1,5km down a road on the right hand side. There may be a tuk-tuk waiting to take you and the going rate is 10,000 kip/person.
Tadlo waterfalls. There are 3 waterfalls within 10km of Tadlo. The first is right next to the village on the bridge (Tad Hang), the second (Tad Lo) is about a 1,5km walk upstream and the third (Tad Soung) is about 8km upstream. Tad Lo waterfall can be easily found by following the jungle path on the left hand side of the river (facing upstream). You will hear it before you see it, and there is a home-made set of steps to take you down to the bottom of the waterfall where you can swim. You can also hop around the large stones at the top of the waterfall, and even jump off if you have the cahones! (although check the area you're jumping into first!).
Palamei Guesthouse. At the junction of the two main street. Run by friendly local couple, Mr. Poh speaks good english and is very helpful. Usually possible to share nice Lao diner with the family and other guests for 30,000 kip.start at 40,000 kip with shared bathroom. edit
Green Garden Guesthouse. Long traditional house with bamboo rooms. Very nice restaurant open early for breakfast and lunch. Kitchen closes with the sunset. Room: 30,000 kip Bungalow: 60,000 kip. edit
Saylomyen, ☎ 020-227-5542. The cheapest river views in simple huts.30,000 kip. edit
Sephaseuth Guest House & Restaurant, ☎ 214185. Next to the river, an alternative place to stay.40,000-60,000 kip. edit
Tim's Guest House & Restaurant, ☎ 214176, . Run by a local Lao couple, this guest house is definitely the pick of the bunch. The owners are very friendly (even voted Lao citizen of the year) and help support the local community with some of the money they make. Rooms are simple but nice, and the atmosphere and staff are great.50,000-70,000. edit
Mama Pap's Homestay, (The main street of Tadlo, Just after the water refill place.). Very basic 'homestay' style accommodation with a very friendly owner. Double beds go for 15,000 a night, they can easily fit 2 people but don't expect any privacy! Facilities are basic with only a cold bucket shower and no internet but this is easily the cheapest place you will stay in Tadlo. Also serves food, service is slow but portions are huge, as Mama Pap says 'Big food, small kip'edit
Fandee Guesthouse. This is run by a French couple who take care of some local kids. It's very friendly and social with a lot of Lao kids who hang out there. They do family dinners and the huts are nice with a double bed, private bathrooms, hot water, mosquito nets and fan. A hammock outside of every hut. 60,000 kip.edit
Walk back to the main road (or catch a ride from one of the guesthouses). Buses back to Pakse operate many times a day and cost 30,000 kip. A few buses go to Vientiane (via Pakse). Ask a guesthouse for times and just wait by the side of the road.