To get started, click on the java window. Press the space bar or enter at the [more] prompt. Afterward, just explore! The games uses a simple parser that understands a variety of commands. When typing in commands, use normal language. Use articles where appropriate. Use prepositions as needed.
Examine as much as you can (or Look At). To move, type the compass direction all by itself. And read the leaflet in the mailbox for some examples of how to interact with the NPCs (non-player characters).
Please visit the Dwarflover forums if you'd like to start (or read) a spoiler thread for the game.