First the good news:
there is no difference between the verbs ending on -er, -ir, -re, -oir, when forming the subjonctif présent. 2) many forms of the subjonctif are identical with the form of the indicatif
3) the subjonctif is almost always used together with que,
so that it often helps to know, when to use it.
The subjonctif présent is formed whith the stem of the 3rd person plural of the présent adding the correct ending:
il / elle
ils / elles
This form is used after verbs of hope, fear, regret etc. to express something irreal. We will come back to the use more in detail a bit later. If you know Spanish, please not that there are some differences, e.g. the subjonctif is used after the verb éspérer (to hope) in French only in negation, in Spanish also in positive phrases.
He does not hope that we would* give him money.
espère pas que nous
lui donnions de
He fears that you would* descend.
a peur que vous descendiez.
I doubt that you would* see him.
que vous le voyiez.
* Even though the sentences would be fine also without the conditional would, we use it here to express the subjonctif.
There is a number of irregular verbs. Again we recommend to get a verb table from your nearest book shop (or, in case you rather work with the net, get a short cut to www.verbix.com). As usual, the most frequently used verbs are irregular.