That would work fine with saltwater as well. You could do a really nice setup in there with the included lights for a FOWLR (fish only with live rock) setup - and shrimp would be fine as well. The light will not be powerful enough for corals. I'm not sure why it says ideally freshwater - probably the light. I would recommend swapping the included "full spectrum" bulb for a 10,000K or 50/50 bulb that is designed for marine environments, but it is not a necessity.
What you will want equipment-wise:
- Live rock - this will be your "filter" in a SW tank - you can buy mostly dry rock and seed it with a little live to save $$
- Heater
- Powerhead for water movement
- A good hang-on-back protein skimmer would be a good addition - otherwise it would just be more partial water changes.
- Refractometer or hydrometer, thermometer, test kits
- Bucket or some such and a powerhead to mix new saltwater, and likely a second heater to warm it
- Good marine book
In a smaller tank like that, look at the more peaceful clownfish - ocellaris or percula, or any of the "designer" colors of those two. The more aggressive clowns will probably kill anything else you put with them in those close quarters. If you get a pair of clowns, you would probably be looking at 1-2 other small fish. Also no anemone - not enough light, plus they are sensitive and difficult, especially in a new tank.
Blue tang (any tang) would get significantly too large / active for the tank. They are extremely fast growers to boot.
Check out liveaquaria.com and their nano suggestions for a 36g tank:
Nano Fish
I'd also recommend browsing through some of the other fish categories, but keep an eye on the recommended tank size and steer away from anything listed as over 30g.