The Charter of Rights and Freedoms is the law that protects some of your fundamental rights in Canada and prevents the government or someone acting on behalf of the government, like police, from interfering with those rights unless the interference can be justified. Law surrounding the Charter, especially about when these rights can be lawfully interfered with is complicated and very case specific. If you are concerned that your Charter rights have been violated and you want to challenge this in court, you should get the help of a lawyer.
Some of your important rights in the context of the criminal justice system are listed below...
Section 7
Section 7 says you have the right to life, liberty and security of the person. This applies in many circumstances that arise in the criminal justice system, including detention or imprisonment and including the conditions you experience while detained or incarcerated.
Section 8
Section 8 says you have the right to be free from unreasonable search or seizure. We talk about searches here. Both the law that gives a right to search and the way in which a search is carried out must be reasonable.
Section 9
Section 9 says you have the right to not be arbitrarily detained or imprisoned. This is important in the context of arrest. Police must be acting lawfully if they arrest or detain you.
Section 10
10(a) says you have the right to be informed of the reasons for your detention or arrest.
10(b) says you have the right to counsel whenever you are arrested or detained. You also have the right to be informed of that right.
10(c) says you have the right to challenge the legality of your detention.
Section 11
11(a) says you have the right to be informed of the offence you are charged with without unreasonable delay.
11(b) says you have the right to a fair trial within a reasonable time from the time you are charged.
11(c) says you have the right to not be forced to give evidence when you are charged with an offence. This is your "right to remain silent", including at trial.
11(d) says you have the right to be presumed innocent until proven guilty.
There are other rights in section 11 not highlighted here.
Section 12
Section 12 says you have the right to not be subjected to cruel and unusual treatment or punishment. This includes conditions when you are arrested by police and not immediately released.
Section 13
Section 13 says you have the right to be protected against self-incrimination. If you are required to testify as a witness in another person's trial, the evidence you give cannot be used to convict you of an offence.
Section 14
Section 14 says you have the right to an interpreter. We discuss this here.
Charterpedia
For a full list of Charter rights and to read about these rights in more detail, go to the Government of Canada's page on the Charter.