Great. A town you can command. More units are able to be produced this time too. You can build all the new units you've discovered as well as some new unit upgrades. I trained an extra peasant to mine gold and made six to chop wood. You will definitely need to build some farms, as the population cap must be raised to have even this many peasants. Make two to three farms before you reach your population cap if you can to ensure a smooth output of units. During all this, keep your initial attack force at home should the ghouls decide to attack your base. They didn't attack me but I have no idea - they might attack you.

At any rate, as soon as you get some footmen and riflemen available, leave them guarding the base and do some creeping with your heroes/the priest and footmen you started with. Keep the mortar team at home, however, as they'll be more useful when you find some buildings to destroy. All the time you're creeping, don't neglect your base. Get your town center upgraded to a keep and get some guard towers constructed to help your footmen defend it. Build up your forces in preparation for an assault later on.

Reveal as much of the map as possible on your creeping expedition (ignore the ghoul base to the northwest of yours for now) and you'll find some minor treasures and gain some experience for your heroes. There is a shop just east of the center of the map where you can purchase potions and scrolls of protection. I opted to buy one of those scrolls, intending to use it before the next big battle. On the way to the gold mine your troops inform you of, you will encounter a group of golems. The big rock golems hit pretty hard as such you'll want to keep Arthas ready to heal. You could even have Jaina summon her water elemental. After they were destroyed I found I ring of protection +2. I gave the old ring Arthas had to Jaina and let him take the better one as he's usually taking more damage than her.

Now I returned my forces to the base to gather what forces I'd built up for the assault on the ghoul base. A mixed bag of heroes, footmen and a couple each of riflemen and priests was enough for the primary group and I had a few mortar teams in the secondary to focus fire on any defensive buildings I encountered. This worked very well and I only suffered minimal casualties.

Replace anything you lose and proceed east of that base. You'll encounter Kel'Thuzad who tells you some dreadful things and heads off to the east. Finish off anything you encounter and perhaps stop at the goblin merchant to purchase a scroll of healing. You'll encounter some abominations guarding Kel'Thuzad and it will probably be a good time for you to use the scroll. Kel'Thuzad himself is a pansy and will fall rapidly to your forces. In case you didn't notice on your quests screen there were no optional quests here.