If you do not have an excellent relationship with your current employer, i.e. they know you are looking and are helping you to find another job by serving as re

If you do not have an excellent relationship with your current employer, i.e. they know you are looking and are helping you to find another job by serving as references; then only give as much notice as you are comfortable being out of work. Do make sure that you have everything organized and ready for the next person. If you have an excellent relationship then it won't matter since they will be happy for you and are aware you'll be leaving. Do make sure you have the other job prior to giving notice.