For some people their website is their business. All avenues on the internet need to lead back to there. Making sure people will find that website, directly, or indirectly, is paramount, and drives many decisions that need to be made regarding SEO, and their online profiles as a whole.
The rules change a little bit if your goal is to get people to your brick and mortar location. In some ways your job is easier. In other ways it's slightly harder.
Why Your Job is Easier
The primary reason your job is easier is because you can take full advantage of the internet as a whole. There are tons of services out there for listing brick and mortar businesses, and businesses in general. When your website IS your business, you constantly need to worry about a balancing act. Each time you get yourself out there on another service you run the risk of diluting the importance of your website. When someone searches for your area of expertise your website is now competing with your profile on some other site that also lists your expertise. When your website just supports your physical location, you don't need to worry as much about this being a factor. Getting people to your website isn't the goal, getting them in your door is. If that happens because of your website, because of your profile on yelp, or Google Maps, they're still in your business.
Thus, while Search Engine Optimization, and increasing the visibility of your website as a whole are never unimportant, it IS important to not lose sight of your real goal. Your time is finite, and you should always be doing what's going to net you the most gain. Don't spend days trying to move from page two to page one for a specific search, when an hour spent claiming, correcting, and polishing your location on google maps, or Yelp, might net more customers. There are a number of restaurants near where I live where google maps (the data which drives the directions, navigation, and "what's nearby" features of lots of apps on countless smartphones) has the business locations off by almost half a mile. Don't overlook a couple painless hours that could net you tons of real visits.
Why Your Job is Harder
Your job is harder because the person whose business is their website just has to convince someone to click, and reach for their wallet. You have to convince them to get off the couch. The good news is, however, that they're probably already half decided on doing just that by doing a search in the first place. There's also a good chance they're already out and about, which is why it's paramount you invest time in making sure you'll show up in their app of choice.
The main reason this makes your job harder is that when the website IS the business the website is the final stop. Someone is at we-sell-widgets.com to buy something, and those websites only have to convince the user to not leave the website they're already on. Your website is not the final stop. Someone is probably at your website only because they need some piece of information that is going to help them decide to visit your location, or not. Make this information gathering as painless as possible. Don't bury it. Try not to trade style for substance in situations where you have to pick one or the other. (I'm looking at you, flash animated intros.)
What kinds of Information?
You have a real place, with a real location, in the real world. At a bare minimum your address should be prominent. Ideally a map a user can interact with would be present, but simply linking your address to its maps.google.com counterpart is a good start. Directions might not be a must, but they might be a good way to get some local keywords in there. (Local highways, nearby landmarks, etc) This real place has an actual door. Doors lock, and people will want to know when you open, and when you close. Put the phone number somewhere prominent so someone can call with questions. If you're an eatery, post your menu, ideally with prices.
Make it as painless as possible to facilitate getting people in the door. It might be a lot to keep updated if your prices or hours change frequently, but it will almost assuredly be worth it. For every user that complains the website said you close at 11, but you closed at 10:30 last Wednesday, or decided not to come because the food was too expensive, many more will come because they were confident you were still open, or not too expensive.