Most laptop RAM is installed via removing a panel on the underside of the laptop - usually 2 phillips screws. There are usually 2 RAM slots there. Easiest thing to do is remove the panels to see if the RAM slot is there and how many spare slots you have. You can also look at the sticker on your RAM and see what speed it is and buy the same.
If you remove all the panels and there is no RAM visible, you just might have a laptop where the RAM is a bit more aukward to get to.
With a lot of older laptops the RAM can sometimes be under the keyboard which is not advisable to remove unless you know what you are doing. With regards to newer laptops it should be relatively easy to remove the memory flap on the bottom and either replace the existing RAM or add to the RAM if there is a spare slot. Just be careful because some laptops have mini PCI slots together with the memory slots which are for either wireless cards or modem/network cards.