One of the most basic things is that the input circuit needs to be AC coupled so changes in ambient light (and the DC state of the photodiode) do not prevent the data slicer working.
An RS422 line receiver works well as a data slicer. We use half a DS9637 or DS8921 as we used a load of those in some other gear.
The have a schmitt trigger input with ~35 or 200 mV hysteresis respectively so don't need a massive signal and they are rated up to 10MHz data rate.
Connect one input directly to the output of whatever preamp circuit you use, with a resistor to the other input and a capacitor to ground from that second input.
The R-C values need setting so the second input follows the first but slowly enough that it takes just a few bit times to get within the hysteresis range of the RX.
(Off the top of my head, 4k7 and 0.1uF should work).
That gives a fast settling time during the data run-in and good immunity to low speed changes like 100 / 120Hz lighting flicker.
As others say, you really need a 'scope to _see_ the signals for fine tuning things like that.
For the input amp, see the PDF link dknguyen posted.
Of course, if you use the little three-pin IR receivers I mentioned in the other thread, each of those already has all this built in to it: