The town clings to two sides of a deep ravine that have been stitched together by a few rad suspension bridges. Resort hotels are all over the place. Don't stay at them unless you have a few hundred dollars budgeted... but do hit them up for a good soak. Some resorts, like the Four Seasons Spa Hotel, will open their pools to non-guests for around $10 to $20 depending on the time of year. But if that's still too steep... you can also find some wonderful pools in the $5 range.
I really love the Chinese verb "pao" (泡) meaning "to steep" (as in tea leaves). It is the same word used for soaking one's self in a hotspring. So if you would like to have a dip, just say "wǒ yào pào wēnquán (我要泡溫泉)." Which means: "I would like to steep myself in the hotspring."
Here is one of several pools in which I've soaked:
The tea scene in Guguan is decent... there are a few little cafes that serve good tea, fresh juice and snacks to the health-conscious visitors. But the best tea in Guguan can be for found for free in the parks and pagodas. If you see some folks sitting in the shade and relaxing with a portable stove and teapot go right up to them and say "nihao" (你好). Tea lovers from any culture love to meet one another, so ask them what type of tea they are drinking and if you can taste a little bit. Chances are they will share a little and you'll spend all afternoon sipping oolong and chatting.
The trails around town are very beautiful and offer some short, rewarding hikes. As you power your way up a flight of stairs to the next scenic look-out you may hear some other hikers yell "jia you" (加油) as they huff and puff. This literally means "add oil" but is often translated as "step on the gas" or "make more of an effort."
Strolling along the Shaolai footpath (捎來步道).
In addition to the many beautiful hotsprings and hiking trails around Guguan, the travel map that I picked up for free in the hotspring museum (also free) stated the following: "There are other natural wonders in the Guguan Scenic Area as well--a thousand year old sacred Chinese white pine tree and a Pig of Destiny."
I've got to go back and find that Pig!