Joining pictures

Hi all,

I've just got back from the AAO in Australia and from a trip to Mauna Kea
and was lucky enough to be given a private tours of some of the
observatories including Gemini North.

I took some pictures and wondered what you guys use to join them together as
the scopes were far too big to get in one shot and I don't have a fish eye
lens so I took several over a wide area with a view to joining them together
at a later stage

Is Photoshop the way to do it? layers or something?

Thanks in advance

Andy