When you are applying for a job, most resumes will have on the bottom "References available upon request". A good percentage of the time a potential employer will not ask for them but there a few that do. The problem with these recommendations is that it is hard to get a recommendation from a former employer. The reason for you not working there can only be for 3 reasons.
The first reason is you quit and why would an employer who you just left write you a glowing letter of recommendation. Not too likely to happen.
The second reason is that you got fired, it doesn't matter what the reason is. If you get fired then there really is no way of ever getting a great letter of recommendation. So why even try to go that way.
The third reason and possibly the best way is if you got laid off. Most employers in that situation will feel bad for letting you go and they will offer a letter. Take them up on it right away. It could be a general letter; you could make copies if you wish. A boss of a former employee does not write letters or recommendation.
If you go to college, you may want to get a letter or two from a professor. This can show your attendance in class as well as your grades if you wish. It shows you come to class as you would to work and with the grades or progress it will show the interviewer how hard you work.
What is not a great idea is having friends or family write letters because they basically carry no weight with an employer. Why? Because they are your friends and family members. Why would they not have something great to say about you?
Recommendation or references can be tricky and most employers know that because they may be in the safe position that is why they need to hire someone. But there are some stuffy employers who want to see them just to see if you can get them. Your work ethic should stand alone and he is looking at you, so they are getting a feel for what you are like, so why need recommendations.
Some employment applications ask for three at the bottom, they ask for 2 personal and one professional. You may be able to get by with personal reference. The employer never calls any way.