It will be used to show digital photographs as presentations more often than not. These will be more scenic than portrait (such as high mountains of Sikkim and also flora and fauna) so good definition will be important
These will be shown I think through the use of my Toshiba Satalite Laptop.
I am a little uncertain about what to "go for" as this will be my first projector.
It is not necessary to have one with a lot of "extras" just a bit more than basic will suit me fine.
First, and foremost, I don't think that you will find a cheap solution! Most projectors have too low a resolution (800 x 600) for your type of photos to really project well. They are more suitable for PowerPoint presentations. (Set your laptop screen resolution to 800 x 600 and you'll see what I mean!
Look for the highest resolution that you can - probably 1024 x 768. Then, look at the cost of replacement bulbs - they are NOT cheap.
Dependent on the location, think hard about the output brightness (expressed in lumens) and the quoted contrast ratio. In a small semi-dark area, you'll get away with quite low values; but if you aim to be using it in a large, well-lit area, you'll need higher output and contrast.
Not a direst answer to your question, I agree, but it may given you guidance in the direction to go.