Saronite translates into easy WoW gold, and can be farmed in massive quantities in Sholazar Basin, Icecrown and Storm Peaks. Wintergrasp is also a great place to farm it, despite being ground-bound.
Sacred Duty, a prot pally blog, recently posted an excellent example of a simple yet effective saronite farming route in Icecrown.
If you cannot fly yet, I highly recommend Sholazar Basin. Follow the rivers, run around the pillars, and circle the province perimeter. In fact, pretty much anywhere you go, you will find saronite, and the mobs are mid-seventies, unlike the heavy hitters in Icecrown.
As for Storm Peaks, make sure to fly up where you would think you have no business being. Giant cliff walls that stretch for miles and random peaks may be boring, but they do contain nodes.
An hour could easily grant you a few hundred ore. Before you smelt it, check your AH prices for ore versus bars. Because two ore go into a bar, you will want to smelt your ore into bars to sell if one ore is worth less than half of one bar. Otherwise, sell the ore! Jewelcrafters will buy it up for prospecting. Jewelcrafters
Prospecting saronite is very profitable. The probability for a blue-quality gem is around 21%, Scarlet Rubies routinely sell for 70-80g on my server, while raw ore might cost 70s-1g a piece (remember, you need to prospect 5 at a time).
Even if you had to pay 5g for each set of 5 ore, and only sold each ruby for 70g, that would give you 14 chances at prospecting a ruby (one, at least) before you'd begin to lose money, and that is without taking into consideration the profits you would be reaping from the other gems that would be coming out of the process.
As for Wowhead, it estimates that you'd be able to sell a ruby for around 100g a piece! Always learn the average prices for relevant items across days and times, so that you know how to spot a deal.