I was on the Health and Safety Committee at a couple of my old jobs (fast food places lol).
A map of the emergency exits (or just any exits in general) in case of fire and such is a good start. I know you can get lots of posters but not exactly sure where you get them but this is a pretty good website about workplace health and safety regulations
http://www.ccohs.ca/
As for robbery, the procedure everywhere I worked was always 1) give them what they want. no ones life is worth the money in the till. Give them the money.
2) assuming they leave when they get what they want (more often than not they will leave because going down for robbery is a lot less time than going down for murder) immediately lock the doors and call the police. All staff and customers need to stay as you are all witnesses.
3)Have a form ready to go that has things like Hair color, eye color, height, male/female, race, what were they wearing, any distinguishing marks, etc. Have EVERYONE fill one out immediately (that goes for customers and employees). Do as little talking with others as possible until you are done writing down your witness statement. Talking to others will skew your perception and could cause you to doubt what you saw.
For first aid, have accident reports on hand. Write down exactly what happened and have the person sign it as long as they are able (Ie not missing a finger or dead) and you sign it as well with the date. KEEP THESE.
Have a well stocked first aid kit. bandaids, gauze, disposable gloves, alcohol swabs, etc.
Of course, as well prepared as you will be there will always be curveballs. One time when I worked at Tim Hortons we had a lady stagger in bleeding from the head after she has been beaten by a couple girls on the street. We got her a chair, got her a large gauze pad to hold on her head and we called 911. but man how do you prepare for a woman to come staggering in with blood dripping from her head. yikes.
Basically, find out the health and safety regulations for your area and they should tell you how to implement them. Have a health and safety committee. Do a Check weekly or bi weekly (depnding how busy you are where you work). Walk around the building and make note of anything that may be wrong like burnt out lightbubs (especially outside, dark areas at night are never good), anything broken or sharp that may be sticking out, check the first aid kit to make sure it is fully stocked and keep a list inside of what should be in there and how many, make sure that you have wet floor signs and that they aren't broken and that they are used regularly, check any chemical cabinets and make sure everything is being stored correctly. Make a check list and check it off everytime you do a walk around and sign it. If something were to happen and someone got hurt and tried to sue this record will show that your establishment is diligent in following health and safety regulations.
That's all I can think of for now LOL. sorry... super long winded