Age group, number of guests and whether the majority are family or friends all makes a difference.
It can however be difficult to plan out a list of songs to play in order in advance, without knowing how they are going to react to them.
Generally, if you have a good mix of younger and older guests, start off with popular older songs (60's etc)for straight after your bridal waltz and slow dances. It will keep the oldies on the floor a little longer and as long as they are well known the younger guests will stick around as well. Try and get into top 40 within about 15 or 20 minutes of dancing starting, and for the rest of the night, try and group songs of similar genres together so that you play two or three of a particular genre in a row.
If you play a little bit of everything, keep genres together, and finish the night with either girly 80's or pub rock, that is probably your best bet.