craftgrrl | decoupage i think? i dunno

hello everyone. i've always been creative, but i'm very new to crafting. just never had the time before, but now i do! but here is my question.

so i have a little wood end table thing. very basic. i want to basically make it my own custom one, using pictures, postcards and stickers and basically make it a collage on the table. i just don't know how to glue the stuff onto the table and seal it well enough for it to last.

so i ask you this, what is the process i need to go through to achieve this? my mom said she's pretty sure decoupage is what i need to do, but i just want to know if that's right. i can look through the memories to find out how to do that, obviously, i just want to make sure i'm doing the right thing.

thank you much :)