Las Palmas is nicely located - take the street that runs behind the church to south from the main street, walk a block and you'll find it from the right side. The rooms were very clean, and at least some of the second floor rooms (like ours) have an excellent view over the Arenal Volcano. The room was with private bath (hot water) and a fan, and costed $20 US per night. In my understanding the rooms on the first floor are cheaper.
Hotel has WiFi access and a few computers that can be used for free for half an hour, although nobody really seemed to be very interested in how long one uses them. Hotel is also a tour agency that offered many activities cheaper than the ones you find from the central park surroundings. E.g. our volcano trip was not just a car ride to the volcano bridge (that's where many go, and it's quite far from the volcano) but instead a good hike up the hill in the jungle to an observation point.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.