You had listed them as non-accompanying? If yes, then he will have to apply to sponsor them. In Guatemala, dependent children take up to 17 months to sponsor, see http://www.cic.gc.ca/english/information/times/perm/fc-spouses.asp#west It could be a bit less because the 17 months are for 80% of applications for spouses and/or children and the children should be a bit faster because there wouldn't be a lot of background checks.
You can try to apply for a visit visa for them but it is not guaranteed that it would be approved. A visit visa is for people who want to visit and if immigration thinks that the plan is for them to stay permanently, they could refuse.