If you do a google search, you will turn up enough information to plant a successful hay/straw bale garden.  I can get you started:  
How much gardening do you normally do?  Are you new to gardening?  
For a hay/straw bale garden to be successful, it should be planted where you have easy access to water, either a hose or a rain barrel which gets refilled often.  They are thirsty, and require a lot of water.  If water is not plentiful where you live, you might do better planting in the ground.  Of course sunlight is of primary importance!  
I like to put plastic under my hay bales, and fold it up around the bottom 6" of the bale to help keep the water in.  
It takes at least 2 weeks (longer is better) to condition your bales for planting.  They should be laid out so that the ties run parallel to the ground.  (that way, they won't rot).  You condition the bales by thoroughly soaking them, and adding high nitrogen fertilizer according to a "schedule" that you will find with your google search.  One thing that your search might not tell you is that urine is a great source of nitrogen and other nutrients!!!  The  fertilization process will get the interior of the bale "hot composting".  When the temp of the interior drops to a "seed viable level" you are then safe to plant.  Many folks put compost or a good starter mix in the planting holes, and even cover the top of the bale with an inch or two of sterile starter mix and plant their seeds/plants in that. 
It's a good idea to put some T posts at either end of your bale garden to help keep it from falling over as the center of the bales degrades.  Those T posts will also be nice support for a plant trellis.  Good crops:  squash, cukes, herbs, potatoes, tomatoes (flowers can be tucked into the SIDES of the bale!)
I like to place my bales in a row so that the narrow end of the bales face out.  This allows a wider planting bed.   
Caution:  be sure you source your materials from farms that DO NOT apply any herbicides to their crops/fields.