If you were born abroad and gained citizenship based on one or both of your parents being Canadian at the time of your birth, you can not pass citizenship to your children if they were born on or after April 17 2009. If they were born between Feb 15 1977 and April 17 2009, they would have gained citizenship but as 2nd generation born abroad, they would have been under the obligation to spend some time in Canada and apply to retain their citizenship before the age of 28. However, the need to retain was abolished with the 2009 law so if they were not yet 28 by April 17 2009, they would not have needed to apply to retain anymore and would still be citizens.
If you gained your citizenship either by being born in Canada or being naturalized, regardless of whether you were naturalized as a child or as an adult, your children would be citizens. However, as first generation born abroad, they will not be able to pass citizenship to their children.
I think you have probably been looking at the wrong application forms. If your children are citizens because of you, they don't need to apply for citizenship because they already have it. They just need to apply for a certificate so they can prove it and apply for passports. You can find the forms here: http://www.cic.gc.ca/english/citizenship/proof-how.asp
