I think you should consider buying an OV Chipkaart for each of you. See http://www.ov-chipkaart.nl/reizen/. This card is valid on buses and trams throughout the country and on some trains. I believe there are senior discounts but that may be available only to residents.

Here is a photolog of my trip from Haarlem to Keukenhof five years ago, http://tinyurl.com/5nwqzp. The weather is very fickle in NL so I advise that you be loose and pick the first warm sunny day that comes around. Tomorrow may bring sideways rain. Go in the afternoon to allow the tulips to open since they fold up at night. I don't know what a combi ticket is.

TBH I wouldn't bother with an OV chipkaart. You would each need your own, and need to be able to load money on to it.
To use it on the train you need a minimum of €20 on it for each journey you make, and it is a pig to get that money back at the end of your trip.
If you think you will be using public transport a lot within Amsterdam then get a pass which covers a couple of days. For the rest buy individual tickets as needed.
For Zaanse Schans you could book a tour bus which would take yo straight there, and probably include Volendam in the tour too.

There are no discounts on public transport for seniors, unless they buy a discount pass, which is only available to residents.

Do they still have Daag Retour tickets on trains - day return tickets at a discount if leaving after morning rush hours - ask for a Daag retour ticket say if going round trip to Den Hague.

Off peak discounts are only available with a special, expensive OV Chipkaart nowadays.

You do sometimes see offers for cheap all day rail travel in some shops, but now it makes no difference what time you travel. They don't seem to have the specials in teh summer any more either.

With a paper ticket if you returning the same day always buy a retour. It is no cheaper nowadays, but is easier.

Hey guys,
Thanks for the swift replies. I guess I'm ruling out the chipkaart for its non refundable deposit and the refund process.

spaarne> Very nice pictures. The tulip fields looked awesome. Thanks for the tip on being loose with my plans. Definitely loose.

hetismij2> Volendam looks good. I'd probably drop by the TIC to see if there are any tours fit for us.

Retour means return tickets yea?

Oh does the day pass still have the 'All In One' version where a pair of return tickets to Schiphol Airport are included? GVB website doesn't seem to have them anymore. So i guess not yea?

No Schiphol is not covered by the GVB pass - that only covers GVB buses trams and metro within Amsterdam. It doesn't cover Conexxion buses or public transport in other towns and cities.

Depending on where you are staying you could consider the Conexxion hotel bus, or get the train from Schiphol and walk/bus/tram to your hotel/apartment.

If you go to http://9292.nl/en# you can work out which is best.

hetismij2> Thanks. Your answers have been most helpful.