Working in the UK is not easy. You may need to apply for a different visa or get a special permission in order to work in the UK as an overseas students. You will also HAVE TO apply for National Insurance to be legally working in the UK even if you have a work permit/working visa.

For most overseas students (Tier 4 students) who are doing a study level degree or a foundation degree, you do not need to apply for a special permission/ visa to work in the UK (it is depending on the course that you study, please do double check). You are allowed to work up to 20 hours per week during term time and full time during vacations. If you are doing a course which is below degree level, then you are allowed to work no more than 10 hours during term time. If you want more info about working in the UK as a student visa holder, go to the websites below for more information. In general, student visa holders do not need to pay tax (but again please double check, as the laws are changing all the time).

http://www.ukcisa.org.uk/student/working_during.php
http://www.ukba.homeoffice.gov.uk/sitecontent/documents/studying/t4-qanda-students.pdf

National insurance Number (normally I just call it NI)

NI number is a very important number that you must have if you wish to work in the UK whether you are a student or just want to work in the UK after graduated. When I apply for my NI, I needed to get the following documents ready and went to an interview (cannot remember the location, and as far as I remember, there are more than one choices of location, so it would need to be confirmed).

i) A letter either a 'rejection letter'- a letter from a firm/ employer mentions that you could not be hired as you do not have a NI number OR a 'acceptance letter' mentions that you will be hire but you will need to apply for NI number. The letter is there to support you to get a NI number.

ii) Try to bring all the identity documents (i.e. passport, HK ID card [if you are from HK], driving licence] that you have which could prove your identity (name, date of birth, nationality etc).Just bring as many you can because there is no clear guideline for it.
I remember once I had all the documents, I telephoned the department and arranged for an interview. They told me on the same day that my case was successful and would receive my NI card by post within 3months.

I would say getting a part-time job while studying or work in the UK for few years after graduated is very good and smart idea. First, you can learn a lot of things that you cannot get from 'books', like how to make friends with all the kinds of people with different backgrounds and cultures; 2nd, you can earn some extra money to support your study and life; 3rd, working involves you to speak English therefore, your English will be improved a lot and 4th, no matter what you do, you can still learn from it and gain a new skill which you could put it on your personal statement or CV.

I still remember my very first interview in the UK; I was so scared and nervous as I could not even speak and I could not hear anything, once I opened my mouth I spoke to the interviewer in Chinese. Obviously, I did not get the job, but I learnt so much from it which I can say I am getting better for interview. Before each interview I would remind myself that, you might not be able to get this job so why be nervous? Try to be yourself and show them what you know.

Even if don't get this job, I can use this interview as my opportunity to practise my interview skills (remember what the interviews asked and be prepared next time). Additionally, I would have to say DO NOT GIVE UP. I had been there feeling down, hopeless, upset and wanted to give up. Just remember that, everything would stop if you stop job hunting. You can send your CV via the internet but try to hand in your CV in person too, some firms would like to see what you look like and what you are like and they might offer you a interview too who knows!