To follow up with a prior post, contact sheets/logs are probably one of the most important parts of a job search.
When you make first contact, you can write down what was said, and by whom. You can reference this when you speak to someone the next time. Some people have the opinion that you should never miss a call from a potential employer. I do not.
I think it's better to let a call go to voicemail, organize yourself, and prepare yourself to talk to whoever is calling you. Get your contact sheet out, find out what the last contact with them was, and call back. It's much better to make a manager wait a couple minutes to hear you at your best, than to talk to them immediately and have a scrambled idea of what is going on. "Sorry Steve, I was in the other room when you called."
Resumes need to look good. There are computer programs nowadays that compare words on resume to words on job description/posting. The more words that are in common, the better chance your resume will be reviewed by human eyes. This of course is mainly with very large corporations, not a family owned grocery store... Take your time and look at job posting, and compare it to your resume.
Resumes should be neat, and not more than one page, plus one page for references. Everything needs to be uniform. If you have your first employers name in 14 size font, the other employers names need to be to. Your job duties are bullet pointed? Better make sure they all are.
Whether to put dates of employment is a big debate. I think, from speaking to managers, they prefer not to have dates. Dates can give away how old you are, and they don't need any hint of discrimination based on age i.e. you worked for one company for 27 years. Congrats, but that also lets them know you are late 40's at least.