N-FETs are like NPN transistors – the gate pin needs to have higher voltage than the source pin for the FET to open. P-FETs are like PNP transistors, too – the gate pin of a P-FET needs to ...

For small-signal mosfet work, the 2N7000 and BSS138 are good nmos choices. The BSS84 is a good small-signal P-mosfet. For a starter kit of jfets, my personal choice would be the 2N4091-2N4092 ...