Heroes of Larkwood has a series of quests to be completed.
Main quest from Larkwood : Take the explosives to the deepest part of the mines, to stop the goblins from attacking
Elf Ruins Edit
Main quest from Brymor : People in Brymor tell you the sage Mirgis is in the wood to the east, find him and you'll be asked to find a crystal hidden in the Elf Ruins to the north
Witches tower Edit
When you return to Mirgis with the crystal, you get sent to the desert to the south to find the witches tower, once there you need to retrieve something from the witch, them Mirgis can use that to find out what is going on.
Ogre Tunnels Edit
When you return to Mirgis with the witches magic, you are sent to Rygoran, by magic portal. The people there tell you that the ogres have stolen the crystals from the temple meaning they cannot cross to the other islands, explore the ogre tunnels to find all four crystals, put them in the right place in the temple and you can cross to the other island.
Now you've got to the north island, find the Ogre Chieftain Raguld and take the shard from him. Return through the portal to Mirgris.
The Dwarf KeepEdit
When you get back to Mirgis you get some more story, then have to get back in your boat and sail north to Stonebrook, from there you need to travel to the mountains in the north to find the Dwarf Keep, there you need to retrieve the next shard.
When you complete the dwarf keep, sail back to Brymor and go back to Mirgis and you'll be sent to the Southern desert where you pick up some more transport and head to Gargutan
Valley of Giants Edit
In Gargutan you will find directions to the Hidden valley of giants and soon discover that you can't get anywhere, talking to the other residents you'll be told about another town in the north called Cragshore. Go to Cragshore and talk to everybody there, eventually you'll find information about golem control crystals and their location. You are free to search the three ruins in any order you wish, Azaa is easy, both in terms of map and monsters, Buza has much harder creatures in it, but seems relatively easy to navigate, Cazu is harder than Azaa in terms of the monsters you meet, the map at first glance is more confusing, but on closer inspection its a still essentially a straight line to the end with a couple of dead ends, map as you explore it'll help.
Buza is essentially a very small level with a puzzle with some levers, what makes it difficult is the heaps of mean monsters. Work you way through, use the map if required.
Once you have collected all three crystals, it's back to the hidden valley (make sure you find somewhere to save before you go here). As you approach the golum the three control crystals wake it up, now you've got to kill it