Notebook keyboards are smaller than desktop keyboards. A hands-on test is essential in deciding how well a keyboard will work for you. Another option is to attach an external mouse. Touchpads seem to have become pretty much the standard. You will want to work with the devices to determine which one you like best.
Some notebooks even offer two of the pointing devices.
I have had difficulties with trackballs and touchpads and generally plug in an external mouse for any lengthy work session. Touchpads make a lot of sense in theory, but it is very easy for me to drag my thumbs across the pad while typing, moving my cursor accidentally and making a mess of what I am doing, an annoying problem I did not discover until after I purchased my notebook. A modem is required because one of the great benefits of a notebook is its portability. 56K modems are the standard. A network card is also all but essential so you can connect to a network or get high speed Internet access.