Monica, take a step back and think about what you have to test.
first you make a test plan:
1. what do i need to test, application-based or web-based (certain function in program, or on webpage maybe login name, email, etc)
2. how do i test this in actual program (what do you need to click on to get there).
Once you have the basic plan, then you get specific and make test cases. something where you test normal entries (actual email addresses, then test boundaries, something like the email box will not accept spaces or strings without the "@" sign, etc.
Thank u all for the replies.it was really helpful and also the sites each one of you gave me are good.i also went through some other sites and now got an idea to write a test plan.Also found one template of test case. and again just want to clarify the terms in the template.can you please tell me whether T/C# is test case number? and also want to clarify few meanings of this terms.what is C/R#(s) ,start conditions,overall pass criteria? can you please give the exact meanings of these.i found this in template which was already discussed before.