A good ride kit is very essential for a safe and fun ride.  First thing 
first, don't bring anything that you are not going to be able to use.  
For example, if you don't know how to fix a flat, bringing a patch kit 
will not do you any good.  It is recommended that you learn the basic 
skills that are needed for first aid and basic bike repairs.

Items for short ride:allen key and wrenches for all the nuts and bolts 
on the bike, tire levers, pump, patch kit/tubes, chain tool, cresent 
wrench, zip ties, duct tape and a small first aid kit.

For longer rides, you might consider adding cables, brake pads, food, 
water, a bigger first aid kit, crank remover, spare spokes, casette 
remover, and extra clothing.

To carry these items, you can use a fanny pack, jersey pockets, bike bags, 
backpack style hydration systems and so on.