ModernCelt
Find a guild to join. Even some hardcore guilds will let in casual players. I have found being in a guild makes it incredibly easy to get a group together to run an instance. If everyone is not already doing something I can log on, start getting a group together and then if we can't fill a full 5 man group, quickly find 1 or 2 more people with LFG and get going. If the group is all guildies we know there will be no issues with looting and I am even happier when someone wants to need an item because I know it is making the guild stronger.
If you only have an hour to play at a time it might be incredibly hard to ever do Scholomance or Stratholm, they just take too long. Is your plan for a soloable instance to start the instance, get to point A after an hour, log off and then pick-up where you left off later on? If I remember correctly, if you log out in an instance and come back much later you log in at the start of the instance. I guess Blizzard could change that for soloable instances and change when the mobs respawn, but that is a lot of changes to a model that looks like it currently works pretty good.
Later, ~Rehlow