@pondypandy depends on what denomination.
Masorti (Conservative),Liberal and Reform Jews- males and females can become rabbis. Rabbis generally go to rabbinic school where they study for 5 years. YoAnd then they graduate. I am Liberal and all my rabbis went to leo baeck college which has a cohort of 5 students every year. As you can imagine, admissions is competitive. A graduate degree us compulsory and someone I know who interviewed for the college was questioned about his previous academic record. You get some really smart people applying to become rabbis. Of course you have to be fluent in hebrew, established and active in your local community etc etc in addition to being v book smart. So most of these graduates would get a post at a congregation.
Modern Orthodox- not passed down from father to son..there are rabbinic families where most of the sons are rabbis. Again there are a lot more rabbis in relation to population. The orthodox ladies know more about this so best to let them ask. There are also charedi dynasties.
Basically as for types of Jews, I would rank them in order of strictness from least strict to most strict. Strictness is defined by how much you adhere to traditional Jewish law i.e. a orthodox Jew would walk to synagogue while a reform/liberal Jew may choose to use public transport or drive to synagogue.
Secular/cultural Jews- they may have passover dinner but they generally are not religious
liberal Jews- vsimilar to reform Jews but it is a UK movement that diverged from reform Judaism over 100 years ago. Its similar to American reform Judaism. I would call it more 'modern' and radical, because it tends to question more and be more willing to push the boundaries. First to introduce mixed seating, first to recognize gay marriage, welcomes patrilineal Jews, mixed marriages etc etc.
Reform Judaism-movement that started in 19th century Germany. Emphasizes evolving nature of the faith. It is supposedly more conservative than liberal Judaism but in reality there is little difference today. Like liberal Judaism ,it emphasizes that halacha or Jewish law is non binding but the ethical commandments apply.
Conservation (Masorti) Judaism- they believe in abiding by halacha but believe that gradual change is the way to achieve it.
Orthodox Judaism- believes in strict adherence to Torah and halacha. In modern orthodox Judaism (which is what I would consider 'centre' or mainstream in the UK), people lead lives not vastly dissimilar to non Jews (university, watch movies,listen to music) but they integrate the religious observances with their modern lives. So they would go to university but not attend tutorials if it is on a Friday evening. Not wear skin tight dresses either. They would have non Jewish friends but would eat vegetarian food when out with them. Marriages are usually not arranged. They have internet and telly. Watch (and adore) football. But still would keep a kosher kitchen and never switch on a light on shabbat. My mother in law would not
even tear toilet paper (I used to tear for her) on shabbat but when shabbat is over, she uses the internet and watches soap dramas.
Ultraorthodox/haredi- lead a far more insular life. There is a lot said about them and there are a lot of sects so impossible to generalize. They are usually the ones with the huge families, men who learn full time (this is not common in UK, more common in Israel).