i know how soulgems work i just don't know what fits in them and usually i end up with alot of greater soulstones with only a common soul in them , which seems as a loss since they are uncommon and /or more expensive to buy

So what souls fit in a greater or grand soulstone ?

You can check http://www.uesp.net/wiki/Skyrim:Souls

exactly what i was looking for , thank you good sir

Good list. All I knew for certain was that giants were greater and mammoths were grand