It is unfortunate when there is some time in your life when you were unemployed for long periods of time. The thing is to not become too stressed out in these lapses of employment. It is also vital not to skip or gloss over these periods where you were not working. Potential employers are going to sniff out these times so it is important that you deal with them honestly. In most cases, a future employer is going to be more impressed with honesty and more understanding of times when there was an issue finding a job.
If you were incarcerated or unemployed due to a mistake you made personally or professionally, you should be honest about this. Most employers are conducting background checks of their candidates before they are even called in for an interview. They are going to find out about this time if it is considered public record, which police and court reports are. By being honest, you stand a better chance at explaining yourself in an interview rather than being passed up.
It is not uncommon for many people, especially in highly technical positions, to be unemployed for long periods of time. It is how you spend this time that really matters to the prospective employer. If you decided to take some college refresher courses, make sure you note that when you list your schooling and throw in a brief statement regarding it in your cover letter. If you volunteered to keep you busy, note that as well. They simply want to know how you spent your unemployed time. If you simply sat at home watching the television and waiting for the phone to ring, you may not be considered self motivated enough to get the interview.
Illness or Injury to You or a Family Member
Some may have periods of unemployment due to an illness you or your family member has suffered from. There are some who may have to care for a loved one who is terminally ill or who has suffered from a serious accident. These times are understandable and even if you were the one who was ill or injured, you should be forthcoming about this especially if it is going to affect your job performance. Remember, if you are fully healthy now, or if your family member is doing better, you cannot be turned down for employment unless it affects you now.
The main point to remember when you have lapses in your resume is to be honest about how you spent your time while unemployed. Keep yourself busy and take some local community college courses or volunteer your time. This looks great on your resume and is going to show your future employer that you are motivated to get back to work. If you or your family member was injured and you are now able to return to work, you should also note this on your resume and cover letter.