The CLB is the Canadian Language Benchmark. It is used by the Government of Canada to determine which level of English you have achieved, and whether or not you qualify for a LINK program, and is often available for free for people with PR or citizen immigration status (there is a fee for Temporary Foreign Workers).
The CELBAN is the Canadian English Language Benchmark Assessment for Nurses. It is more like the IELTS and TOEFL. Where IELTS is required for immigration, and TOEFL is required by colleges and universities the CELBAN is required by Canadian provincial colleges of nursing. It is a discipline specific English proficiency exam, and is more official than the CLB. There is a fee for everyone taking the exam.
The CELBAN is often the first step of becoming a nurse in Canada. For information about the required mark go to the College of Nurses for your province. Search their website for Internationally Educated Nurse Applicants.
I hope this helps!
Search dear-kim for more questions and answers, or search CELBAN on facebook or youtube.
CELBAN Preparation courses are available for writing and speaking, and there are resources for reading and listening. Have you tried a google search of "CELBAN Prep"? If you search that with the word "info" you will find everything you need.