WARNING::: All the freqs below are approx so move the knob back and forth to get the right sound.
So you're saying that you record electric guitars, bass and drums.
ELECTRIC GUITARS:
100 hz = bottom end, grunt
but be careful boosting this frequency because a short distance away, at 200 Hz, you run into a frequency that, when present in large amounts, has the effect of throwing a blanket over the sound and destroying all clarity.
500- 600 Hz = the body of the guitar
3k - 4k = psycoacoustic excitement, gives the guitar some edge
but don't hit this freq too hard or it will give you a headache.
5k - 8k = brings out the sibilants of the strings, again don't overuse.
10k or so = this is the freq that is used to bring out the sound of a crash cymbal, so if your guitar is playing power chords over cymbal crashes then accentuate the 10k to make the cymbal and the guitar blend together.
KICK
Give the upper freqs a boost at about 3k, and sometimes a push between 6k & 8k which provides kind of a click.
100Hz = bottom end, but you can go lower even to 40 Hz depending on what you are going for, like if you're going for some special medium that can plaback those frequencies.
The amount of boost depends on instrument, but is relative to the amount of boost I do at 100Hz.
Boost the 8k about one-tenth the amount boosted at 100Hz.
Boost the 3k about two-thirds the amount boosted at 100Hz.
SNARE
1k - 3k = the bang range
5k = sound of the snares and the stick hitting the skin
100Hz = you can boost this before it hits the tape to make the speakers push a lot of air, and then the listener can physically feel the pulse of the snare and the kick drum.
It is important that you don't want the snare to ring into the next beat, there should be a direct connection between the tempo of the song and the EQ of the snare.
BASS
I don't know if you're doing singal signal recording or combined signal recording but start by giving it a low end boost at about 100Hz, But you can go lower even to 40 Hz depending on what you are going for, like if you're going for some special medium that can plaback those frequencies.
Don't push near 200Hz or it will get muddy
800Hz = The harmonics that make it easier for the listener to detect the pitch.
3k and 5k = Hear more of the attack when the finger or pick plucks the string.
I know this isn't complete but it will get you started.
