This is my current project: https://www.reddit.com/r/dwarffortress/comments/4n6yun/ochre...
The first stage was simply to dig out a big hollow cavern, with walkways and a central pillar of stairs. A chap has given me an idea about a bridge over the volcano and I think I will have a drawbridge block off the entrance once the invaders are quite close, and then marksdwarves can shoot down on them. We expect people to dodge off and into the magma.
I play MasterworkDF, which adds a number of things such as guilds and castes, but LNP is a good place to start.
For anyone who is a bit scared by it, just persevere. Start simple. Seven dwarves. Dig a hole in the ground. Start a mushroom farm. Brew some wine. Get a carpenters workshop. Make some beds. And barrels. And take it from there.
It'll be worth it.