Get really good at flat bench, as in perfect form and a good base of strength, before you worry about incline or decline. If you have a good arch on your flat bench then it will basically BE a decline bench press, which is a good thing. If you have questions on bench press form we'll be happy to help.
If you also include dumbell presses and dips then you'll have all the movements you need for great chest development.
As an aside, please work your back just as much if not more than your chest. There are more muscles in your back, and they are far more important to your development as a lifter when compared to your chest. As a general rule, you should do at least 1 set of a pulling movement for every pressing movement you do. That means for every set of bench presses, dips, or overhead presses, you should also do at least one set of some sort of row or pull up at some point during the week.
Please trust me when I say that you will be much happier with your overall development if you follow this advice.
Last edited by Soldier; 11-17-2011 at 10:00 AM.