No frequency would help because arms have the wrong form. A bird can't fly if you cut four or five important feathers, however fast it flaps its wings, it has just to wait until they grow again.

Big birds flap their wings slower than most small ones. Often they just glide, not waving their wings at all.

A human can remain airborne for quite a time with the help of a hang-glider, which doesn't flap either.

In principle you could become airborne by moving your hands down with palms facing the ground and upwards with palms vertical.  That way there would be a net displacement of air downwards and Newton's third law would give you lift, but it would be hopelessly inefficient compared with an aerofoil, and your hands are the wrong shape anyway.  Say the area of both palms minus the area of both hands side-on is 100 cm^2= 0.01m^2.  You weigh 80kg = 800N and you're getting net lift half the time (the half cycle when your hands are moving downwards.  Air density is 1.3 kg/m^3 at sea level. Then the minimum velocity of your hands to achieve lift-off is SQR (1600/0.012)=365m/sec, which is slightly more than the speed of sound.  

Any estimate I give would just be hand-waving.

Simply flapping your arms up and down won't work at all, you'd need to change the orientation of the arm between the upstroke and the downstroke, similar to the way one swims, underwater.   paying attention to just the forearm and hand,  the approximate maximum cross-section for the downstroke (for me, anyway)  is somewhere around 60 sq.in. the approximate minimum cross-section for the upstroke, is  around 20 sq.in. that leaves 40 sq.inches of surplus cross-section per arm.  (this is assuming that the velocity profile of the upstroke is identical to that of the downstroke.)  so.. with two arms, we have 80 sq.in. of lifting surface.  out of which we have to generate 200 pounds of lift.   since the arm is moving down only half the time, and has to accelerate to and from 0 at the ends of the stroke,   the lift should be roughly equivilent to 1/4 that provided by a similar cross-section in continuous motion.   wind pressure in psf is 

.000256 V^2  where V is in miles per hour?   I think that's right.

so 800 x 144/80 = .000256V^2 requires a V of 2372MPH.  Since the total stroke cycle is about 4 feet,  that should work out to a bit over 35KHz.

Of course, your "wings" will be breaking the sound barrier on every stroke, which will screw up the calculations even more, but that should be about the right order of magnitude.

It is completely related to how much volume of air your hands can displace in a single stroke. Use this volume of air to find the mass of air being displaced per single stroke. Lets say you can manage n strokes per sec aka your frequency. Then you can find mass of air displaced per unit time. If you remember your conservation of momentum, this will give you the upward force you experience. SInce this has to be atleast your weight or more, you can work out n, which is the number of strokes per sec. My bet is this will be some ridiculous sumber and thats why we dont fly.