Salaries and opportunities for advancement
We should be honest and say that this is not a career for those who want to earn vast sums of money.
Which is not to say that salaries are poor - but you really must not see the salary as the main attraction of the career. Rather, it is the general excitement of working in and with your own subject, passing on your knowledge to others, and generally being part of a lively academic community, that should drive you.
Salaries of lecturers are near-enough standard for the whole country. The salaries are based on incremental scales which can be found, for instance, on the website of the University and College Union. New lecturers in a first appointment are likely to start at a salary of very roughly £25000, and may reasonably expect to proceed by annual increments to the top of the lecturer scale which is currently in the upper £30000s.
Promotion beyond the level of lecturer will lead to higher salaries - currently up to around £45000 for a Senior Lecturer or Reader. Promotion to these levels is very competitive and depends on the quality of the individual's work. These levels carry considerably higher responsibility, usually in terms of academic management for Senior Lecturers and in terms of high-level independent research for Readers. In some universities, the terminology used for these promoted posts is a little different; for example, the title Principal Lecturer is sometimes used.
The pinnacle of a university career is to be appointed a Professor. This is an extremely important promotion, usually dependent on an impressive research and publishing career, and normally backed up by reports from eminent external assessors. Professors carry very large responsibilities, usually in terms of furthering the department's research. This might involve setting up new research teams; it almost always involves bringing new research funding into the department. A Professor might also be the Head of a department, or even the Head of a group of departments, responsible to the university for their entire conduct. Not surprisingly, Professors usually do not undertake so much teaching, though in nearly all cases they do some.
[Incidentally, to avoid possible confusion, we should say that in the USA and in some other countries the word "professor" is used in a different way, to refer rather more generically to all university lecturers. For example, a newly-appointed lecturer in the UK is likely to be referred to as an Assistant Professor in the USA.]
Coming back to the start of a career as a lecturer, some appointments are permanent and others are temporary. The latter are usually limited to about two or three years, though sometimes with the possibility of renewal. Appointments are always subject to a probationary period, which can vary from a few months to three or four years. Usually newly-appointed lecturers are assigned a more senior member of staff to act as a mentor and help them through the early stages.