I think Scandinavia is quite safe in terms of crime, etc. If you're off hiking in the wilderness by yourself you face the same dangers as you would hiking solo anywhere in the world - with the added complication of potential communication difficulties.

There's probably some international hiking forums out there with info on Scandinavia. For general travel guides to Scandinavia you can get guidebooks like Rick Steves, Lonely Planet, and Let's Go! (which focuses on student travel). All of these will include information on hiking and the like. They may not be focused on hiking, but they will likely have more than enough info to get started planning.

If your main aim is hiking with gorgeous views, don't limit yourself to looking at just Scandinavia, though.

CR