Shelter starts with protection from the elements, but goes on to include safety and security, too.

Safety and security applies to your business at all times, i.e., before, during, and after work hours During the business day, you want your customers to feel safe in the neighborhood that your business is situated in, as well as inside your store (e.g., safe from crime, injury, fire, etc.). After hours you want to safeguard your business, inventory, paperwork and reputation with a good security system.

I recommend: ADT has an online questionnaire that can give you an idea of what to consider for your security needs based on some basic criteria, i.e., size of business; number of employees; number of doors; and type of ceiling.   Their solutions cover a broad range of security issues, including: burglary; employee productivity; employee theft; vendor theft; robbery / assault; vandalism; worker's comp; slip and fall liability; drugs in the workplace; shoplifting; workplace violence / harassment; perishable spoilage; flood detection; outside safety; and intellectual property loss. 
Note:  Keep in mind that it is important to have a solid Internet Security System in place for your online business as well.

Get a strong door so a wolf can't come and threaten to 'huff and puff and blow your door down'.

Just like the story of "The Three Little Pigs" consider what kind of door is appropriate for your needs, yet still easy enough to maintain. Know how durable the door and its components (lock, hinges, etc) need to be (heavy or light traffic area)? How concerned are you about things like: break-ins; vandalism; or extreme weather or natural disasters?

I recommend: Typical materials for business doors include:  steel, aluminum, and wood.  When looking for a steel or aluminum door manufacturer, be aware of the further distinction there among: industrial, residential, and commercial and institutional markets.  To learn a few more basic facts about the U.S. Door Industry, see the online summary of a recent Catalina Research study.

Know what type of maintenance your Entry Door requires.

For your curb appeal to be effective, not only do you need a solid and appealing door design, but you need to keep it looking neat and clean, too. How often do you need to clean or polish your door (especially glass or shiny areas)? How often do you need to paint or re-finish the surfaces? Will it hold up to heavy traffic? Is it weather-resistant? Is it energy efficient or insulated enough? Will it hold up to use or abuse, regarding scratches or dents?

I recommend: Keep a clean appearance both inside and outside of your store, including the doorway.  A sloppily maintained facility will overshadow and negatively impact the best of products.  First impressions matter.

Choose a custom-made front entry door / storefront instead of a standard manufactured door.

Even if you are working with a limited budget, it may still be worthwhile to invest in custom-made entry ways, rather than going with generics, especially if you invest in materials and a design that is expected to hold up well over time.

I recommend: Consider consulting with an expert or specialist in the type of door you are considering.  A company like Steiner Doors that specializes in custom architectural aluminum door and window designs has the experience to recommend an appropriate style for your business and can even incorporate your logo and/or street address into the front entry door's design.  These doors can be made to architects' specifications with styles ranging from French Doors, to Herculite Doors, to Custom Aluminum Front Entry Doors (that don't have an industrial look), to Architectural Doors (with styles from the 30's and 40's, a great fit for some cities), to Custom Retail Alumimum Storefronts.

Your physical location is an asset, use it wisely.

Especially if you've chosen to establish your business in a big town or big city, both for the fancy address, but also for the 'foot traffic', be sure that you don't squander that investment by not using your facility as the promotional opportunity that it can be.

I recommend: Use your facility to sponsor free or invitation-only after-hour events, such as:  an Open House; a gallery exhibit;  a frequent customer 'Meet and Greet';  a new product line debut;  a media invitational;  etc.    When choosing this option, have some finger food or hors d'oeuvres on hand, and also some promotional products imprinted with your logo and business contact information.  Whether it is for an exclusive after-hours audience or as a contest for regular day-time customers, invest in a quality promotional products such as:  promotional apparel & caps; promotional bags & totes; pens; keychains; etc.

Learn key door terminology so that you know what to ask for.

It seems like every single object in the world has an industry or association devoted to it. For doors, that holds true. Within this door industry, there is also important terminology to be familiar with.

I recommend: Some door manufacturer's and door industry group's that list glossaries or key terminology lists & FAQs on their websites include: Lowe's; Peachtree; and the Window & Door Manufacturers Association.