There are 2 kind of ielts test.
Academic ielts and general training ielts. For studying abroad, academic ielts is needed. Ielts is accepted on europe and australia, especially UK and australia. But now, some american country accept ielts to. To ensure what kind of test which are accepted, the applicant must check universities website directly. University web in abroad is very complete. Detail prequsite and other requirements is shown there.
There are 4 section in academic ielts test. First section is listening, and then reading, writing and speaking.
Listening section consist of three kind of native speaker dialogue or monologue. You need to learn every type of listening section. So far as I know, the time you need are 40 minutes. Listening test in ielts is special. You must fill missing words in uoir sheet during listening the monologue or conversation. But you will be given 10 minutes to transfer your answer to answer sheet.
Next section is reading about 60 minutes. There are three passage need to be read throughly. You need good scanning and skimming ability to finish reading test successfully.
Other part is writing. There are two task in writing. First task is describing a given table or chart. The second is make argumentation due to given topic. Remember in first task, you do not recommend to give arguments, only describe it.
The last part is speaking.