Roads mainly trace the coastline in West Iceland, with a few mountain passes and more inland roads in the rural area northeast of Borgarfjörður. The Ring Road bypasses large sections of the region, including Snæfellsnes and Dalirnir, meaning traffic can be very light. Although most roads are paved, the very tip of the Snæfellsnes peninsula is not, nor are some of the mountain passes. If driving, beware that in some places the road on Snæfellsnes sits on a very narrow ledge, with a long and steep fall to the sea below.
Driving on your own is the most flexible way of getting around, but there are some bus routes operated by Sterna (http://www.sterna.is/en). Hitch hiking is an option for those travelling by bus who want to reach destinations not served by the bus system.
To get to the islands of Breiðafjörður, a boat is needed. Only Flatey is served by regular ferries from Stykkishólmur, crossing over to Brjánslækur on the south coast of the Westfjords. If you wish to visit other islands you will need to arrange transportation locally, but frankly most of them are small and without much to see.