You can also smith yourself a grappling hook to make getting around that little bit easier - with a rope attached you can scale walls, cross rivers and climb cliffs if you have the agility and strength to do so.
Take a look at our Knowledge Base for specific information and talk to Hirko, Hura and Holoy, the crossbow salesdwarves who are located in Keldagrim, the pub under White Wolf Mountain and the Dwarven Mine. Hirko even has a useful way of storing all your new bolts so they don't take up too much of your precious bank space - for a price of course!
If you've completed the Knight's Sword quest you also have the option of Smithing yourself a beautiful blurite crossbow and bolts. Please note that blurite items and enchanted bolts are not tradeable.