There are several methods that can be used for installation so you can adapt your method to suit the ceiling you are covering. Each has its own merits and drawbacks which are discussed in more details here.
Sticking The Panels
PVC ceiling panels can be stuck to a ceiling with a standard panel adhesive such as No More nails or Gripfill.
Most of these adhesives have a decent initial grab but gravity can sometimes get the better of the grip before the adhesive is full cured so it is best to use some props to hold the panels in place while the adhesive sets. Alternatively you can use adhesive in conjunction with a staple gun - the staples will help hold the panels in place while adhesive sets.
Stapling The Panels
This is a very fast method of installation using a staple gun. he panels are stapled through the thin tongue so there is no need for very long staples or a high power gun - a basic cheap and cheerful staple gun will work just fine. The success of the process will depend on the substrate into which you are fixing, but the panels are quite light so they should hold in most circumstances. Again, you can use a combination of staples and adhesive.
Fixing With Screws
There is no real advantage in using screws to fix panels - their main advantage is that they enable the panels to be removed (but it is possible to remove staples if you are careful which have the advantage of speed of installation over screws). By screwing through the tongue the screw head will be covered by the next panel so they will not be visible.
Install Using Battens
If you have a very uneven surface on your ceiling you might need to use battens to level the area before you install the panels. Once these are screwed in place (usually fixed directly into the joists) the panels can then be fitted using one of the options described previously.