I just wanted to add, whilst I agree with a large portion of tonshcabe’s informative post, I believe this small bit of information may be very helpful.
It is not a commonly held view(maybe out of the box), should you adopt it or at the very least(more likely) be aware that it is possible,you will experience a massive rise in confidence in your ability to produce professional sounding mixes and most importantly, rely on yourself.
I have heard so many in response to questions similar to this, which I have asked as well…“don’t expect your mixes to sound like professional mixes,they get their mixes done by professional so and so, with expensive so and so and” …well you get the drift.
Seriously…like 10s of times I have seen this exact response…uncanny!!
I being hard-headed and implicitly trusting my own opinions on matters, always expect my mixes to sound like pro mixes…wherever the hell they were mastered.
I don’t even use monitors…(yes seriously)…I use free plug-ins exclusively(got my eye a few pay plugs worthy of my arsenal though).
I give a lot of advice but I will not tell you how I do it, as nobody told me how(plus it may not even be productive for you). Its just I had so many people saying you need monitors you need professional mastering…that I was like no f$%^^ off, I can f&ing do anything, and studied the sh&&^ out of pro tracks and figured out how to replicate the formula so to speak…and all the information that helped me do it is freely available or cheaply available…(CM mag and Future Music as well no matter how many may knock it, granted I agree with many sentiments as I don’t buy them anymore)
It was simply obsession that got me there…anyways the other reason I won’t tell you is that I do not recommend my methods to any one other than myself, takes a hard headed individual with absolute faith in himself in spite of popular opinion and evidence…if you can use monitors in a treated room or with good room correction software, do.
Other logistical issues made monitors a no go for me as well…no maybe it was necessity as well that drove me (more than maybe, most likely).
Anyways, the whole point is you get what you expect in life. Actions, manifestations etc…many times follow expectations…ever hear the saying, whether you think you can or you can’t, you’re right?
Well the same applies in music production. I expect my mixes to sound professional and so they do. Whilst many top producers do use mastering houses etc, many do not and sound just as good if not better.
Not even remotely steering you away from these options, I am just telling you don’t underestimate your autonomous abilties. 
ps:marcus: maybe it will be easier for you to find the right levels if you send all the drums to a send channel… first you balance them as you see fit in a “drum kit mix” and then, when you listen to all of it at once you only got one knob to control the grouped kit sounds against all the other channels. just a thought.
i’ve read that a lot of people use send channels to gel the drums into more of a unit… applying the same reverb and compressor to the send channel. haven’t tried it myself though.
Re: Maes’s suggestions above…I use this technique all the time, however, I process my high end percussion separately and don’t bus them…I do, however, send all of my tracks to a common “room” reverb.
pps…I will give you these hints though in response to your question, as your interests dictate you may be trying to produce DNB…in DNB and Dubstep…the sub is almost always loudest(99% of the time), followed by the snare, then the kick.
Hats, cymbals are quieter (dbwise) than sub,snare and kick…
sometimes the kick is same level as snare…depends on what feel you are going for