Offline Marketing Any Tips On Approaching Local Businesses?

I am thinking about doing some offline marketing, but not sure the best way to go about approaching local businesses. My idea is to contact establishments who have a limited to zero online presence. Thinking along the lines of setting up a google reviews page, creating a nice company video and putting it on youtube, creating a facebook page etc.

I have a few ideas, but I'm not sure which would get the most results.

Ideas I have:

1. Create a sales letter outlining my services. Add a business card and pop into business and hand to boss or secretary.
If going with this approach, should I angle the letter in a sales pitch manner or just a quick rundown of my services? In other words, do I need to tell them all about google reviews and how it can help get them more clients in the door? I don't want to come across as a door to door salesman trying to sell hyped up crap. I'm guessing a basic sales letter...

2. Set up a website, email managers and direct them towards said website that might be a little "pitchy"?

Any other ideas would be appreciated.