Could someone please suggest a few commonly available and general purpose FET's . I would be using them primarily for switching small currents (<100mA) and also for making switched capacitor circuits.
Switched capacitor circuits usually require FETs with separate bulk terminal to be able to switch birectional voltages. To reduce charge injection, CMOS analog swiches would be the preferred solution. There's only a small choice of MOSFET with separate bulk, e.g. former Vishay SD211.
Thanks you very much for the suggestion. I will look into CMOS analog switches, maxim seems to have a good selection. But i also wanted to know a few part number of commonly used n and p channel FET's....
As FvM has mentioned, switched cap circuits are unlikely to be implemented using discrete FETs as parasitic capacitances are likely to kill whatever performance you have. The basic rule for switched caps is that if you want it fast, you need small caps. But if you use small caps, you need small parasitic caps.