Sound/Lights - Make sure the agreement specifies who provides/pays for the sound system (PA) and the sound operator, as well as when/if there will be a sound check. Also, specify who provides/pays for the lights and light operator.
Insurance - Although this is often overlooked, it is important that the club have a liability insurance policy in place which covers the artist's performance so that if some injury occurs in relation to the show on the premises of the club, the artist is not liable.
Cancellation - From the artist's perspective, if the club cancels, it should pay the artist a specified amount of damages (preferably the guarantee).
There are some other points that can be covered such as promotion/advertising commitments of the club, allowing the artist to sell merchandise at the club, etc. Above all, make sure the club signs and dates the agreement.
By entering into the above agreement, the artist will find that there are less hassles because there is certainty as to what is to take place and how the artist gets paid. Although there is always the possibility that a club might renege, at the very least, the agreement offers some form of legal protection.
Ben McLane Esq