Cambridge ESOL: Certificate in Advanced English (CAE)
You can practice your writing skills by writing short pieces and posting them here for our comments. You can find listening comprehension practices on the internet. For example:
Randall's ESL Cyber Listening Lab - For ESL/EFL Students
There are many more.
Speaking is more of a challenge. I assume you have an English teacher at the moment, or are you trying to get yourself through the exam? If you don't have a teacher, I would recommend at least finding yourself a native English speaker as a conversation partner for an hour a couple of times a week.
Student or Learner