http://www.pa4tim.nl/?p=3775 about ESR
If you then use the find function on my site you also find pages about measuring DC leakage ( and reforming caps including a schematic for a reformer/ leakage tester and simple ways with a bench supply.
If you want to learn more about impedance, i have a network analysis tutorial there too ( 8 downloadable pdfs) it is written for vna users but it are the basics in NA. A good start is the free Agilent download of their impedance measurement handbook ( but for network analyses you need a good understanding of electronic basics and complex notation, NA is not about measuring antennas and filters like many people think ( and it is most used for by amateurs, but it is for most about component behaviour on and off pcb)
The ESR goes exponential from infinity at 0 Hz to a lower value around 10-20 kHz, then it decreases further to a minimum, for big caps between 50 and 150 kHz, after that dip it increases again due to skinloss and dielectric loss. ESR is not a very usefull value on its own. For instance the ESR of ceramics caps is low, but the ESR of a good 100 pF cap can be over 1000 Ohm.
If you measure 2 Ohm at 10 kHz, this can be low or very high. This depends on the value of Xc and so C. If you have a good LCR meter it gives you D, this tells about the quality of the cap, regardless of other things. D is specified in datasheets, but D is given for a frequency. The standard is 1 KHz and 120/100 Hz. A D of 0.01 at 1 KHz, will be around 0.1 at 10 kHz because ESR decreases little but reactance decreases 10X. But that is all in the link. There are also pages about measurements on known bad caps that I found donig a repair. I measured them in several ways to compare.
Best LCR meters are bridges, alltough modern on cirrus chipset based ones come close. ( i mean affortable LCR meters, real good digital LCR meters have been around much longer but very expensive) I have a bunch of bridges, restored most of them and kne how to use them, mail me if you want to learn how to use it, But tell me the brand-type brigde you have and if rather unkown a sharp picture of the front. The fact it needs a seperate oscillator (and detector? )makes me think it will be a good one, Wayn Kerr, General Radio or ESI perhaps ?
On the site of Conrad Hoffman, also a member here if I'm correct, there is a lot of information about bridges too.