I think its great you are enthusiastic and want to enter your beer in a competition. I think you should go for it no matter what. I will try to give you a heads up from a judge's perspective, though, so that you can understand where we are coming from, and also so that your first experience in a competition isn't your last due to being unprepared/unaware.
The judges are looking to see how the beer fits its style, in terms of Aroma, Appearance, Flavor, Mouthfeel, and Overall Impression. Production flaws, and stylistic aberrations discount from that goal.
We use these guidelines so that we can get beyond the "apples vs oranges" comparisons. Without the style guidelines, things become totally subjective. Under those conditions, a judge that prefers massive bitterness will only score IIPA's highest and things like Helles go by the wayside. It turns into a crapshoot. Did my beer get evaluated by someone who hates (xyz)? No, we can't have that. So, we created the style guidelines.
Even when we do Best of Show panels, the thought is always "Is this a better example of XYZ than that is an example of ABC?". It grounds the competitions back into a reasonable set of rules that everyone can generally agree upon, and puts the entries on an even keel.
However, it's not perfect. Unfortunately, there are well made beers that sometimes get lost along the way. For example, there are a few breweries now making German Pilsners using Cascade and other American hops (German pils grain bill, American hops, German yeast, etc). These beers are often wonderful, but if you look at the criteria for what makes a classic German Pilsner, grapefruity hop character is out of bounds. This beer will do poorly against a style compliant German Pilsner.
So, a beer that is entered in a classic style category is expected to match the characteristics of that style. An entry that is outside of those characteristics (such as too bitter) can taste and smell great in its own right, but will typically not get above moderate scores (low 30's or so). A good judge will still compliment a well made beer while still giving it a low score.
If you know that your beer is a true "tweener" (ie, between styles), then you can always enter it as a specialty beer and see how it does there. Perhaps you could enter as a Session-strength English Brown IPA in the Specialty IPA category?
Note that those categories can get big because a lot of guys go out of their way brewing all kinds of crazy concoctions on purpose, so be aware of that, too. Some beers are simply meant to be enjoyed.
All that said, enter it anyways! Set your expectations accordingly, if you know going in that its not completely inside the style guidelines. But do your best to match it up with whatever style it fits best, like Denny said. You will at least get an honest unbiased evaluation, nowadays almost always by someone with a trained palate. They may point out things for you to improve, or they may confirm that it's a great beer!
Either way, that beats hearing your neighbor say "Damn that's good", because he just wants free beer but doesn't really know much about beer.