Your student visa requirements are dependent on your country of origin, there are different requirements that are dependent on variables such as in you are an EU/NON EU national, are coming from British overseas territories, your immigration status etc. For more specific information, it is recommended that you attend a pre-departure briefing where someone will be available at the end to answer all your questions.
Alternatively here is a generalized list of hints and tips when it comes to obtaining a student visa and what to avoid so you do not put your stay in the UK in jeopardy.
There are different visas depending on the duration of your courses. Certain student visas cover you only while you are attending an English language course while others will cover the duration of a degree. If you finish a language course and want to stay for an additional qualification, you will need to reapply for a new visa. DO NOT over stay your previous visa or it may negatively affect your rights to remain in the UK. Below are the types of student visa available to apply for:
Most EU nationals (except Romania and Bulgaria) are allowed to work in the UK while studying. However if you are not an EU national, you are not allowed to work in any capacity whether employed or self-employed. Unless your visa expressly says you can, do not work while in the UK, if caught it can void your visa and result in deportation, and not completing your qualification.
For more detailed information on how to obtain a student visa for the UK, visit the UK Boarder Agency website.