I like to have a few directories on my web server for easy access from anywhere. Most importantly, /files/

Of course, Pelican can handle such things. All you need to do is set STATIC_PATHS in your pelicanconf.py

STATIC_PATHS = ['files', 'share', 'public', 'docs']

And make sure your static directory is within content like below:

├── first post.textile
├── second post.textile
├── number three.textile
├── files
│   └── some document.pdf
├── pages
│   ├── about.textile
│   ├── contact.textile
│   ├── links.textile

Pelican will nicely copy these static files from content to output without processing them in any way.

See here for more details: Pelican Docs