Thanks for the heads up
I've just recently moved onto all grain beers and, though still doing some clone recipes, I wouldn't mind taking a stab at some recipes of my own. Though I can look up the guidelines of a certain style of beer and I have a general idea of what hops are used together and in what style beers, I'm anxious to take a stab at a recipe of my own.
What do you suggest, just dive in head first or can you suggest any reading material?
First, buy commercial brews that use exclusively (or primarily) a single hop to learn what it tastes like.
Idea #1: Design around a hop
Narrow it down to one or a couple that you like. Pick a style that you think you could use those hops in successfully. Look at similar recipes in the style (ones that use similar hops) for an approach to a grain bill
Idea #2: Design around a style
Pick a style. Look at a bunch of recipes in the style to figure out what kinds of hops are common. Pick a few that you like, or that you think are similar enough to work well.
Either way, you can then pull out your brew software, give a go at designing a recipe, and post it here for advice.
Also remember that it's really all a matter of taste, and that it's especially difficult to screw up simple recipes. You can do a single malt/single hop of, say, Marris Otter and almost any hop that you like and it's going to be a good beer as long as you get the hop/gravity ratios in the right ballpark.
Likewise, you can almost always throw in a pound of crystal 60 or Vienna or biscuit if that's the flavor you want and use some common high-alpha hop for bittering and one whose flavor you like for later additions. Whether you do Galena or Magnum or Northern Brewer for bittering will have some effect on the flavor, but it's almost definitely not going to ruin your beer (especially if you match it with even a remotely similar flavoring/aroma hop).
The same goes for picking a yeast--you obviously don't want London Ale yeast in your pilsener, but as long as you're in the right ballpark you should be okay. US05 vs. Nottingham vs. Pacman will change the flavor some, but if you're making, say, a pale ale or IPA they're probably all going to result in good beer. Obviously there's a real flavor difference, but that's the joy of designing a recipe--you can pick what you like.
Now, once you start messing with larger amounts of non-base ingredients or with really strong ones (peated malt, roasted barley, Sorachi Ace hops, Belgian yeasts, etc) then you want to be a little more careful and have some idea what the outcome is like (probably by having brewed with them in another recipe before). But as long as you start off using baseline stuff and working within some reasonable IBU/gravity guidelines, go crazy. Have fun. Design a beer that _you_ want!
And then post here--someone will let you know if things look too crazy. And it's always good to get positive feedback beforehand, too. My first recipe posted I ended with the line "Does this seem like an insane idea?". There were definitely a lot of suggestions (many of which I incorporated), but hearing the first or second reply say "Au contraire, mon ami. It is a *fantastic* idea." was nice to hear and let me know that I already had an actual honest-to-god beer recipe--I was now just trying to make it a *good* beer recipe.
And it turned into the best beer I've ever made.