1995 polo wont start?

I get all the lights on dash and the battery is only a year or so old, when I try top turn it over I get nothing at all, all the lights on the dash stay on though. i have been able to get the car started by bumping it, could it be the starter motor? and how easy is it change?

when I try turning it over I firstly get a noise from the engine (electrical noise) then clicks twice, also I cant quite locate the starter motor, I thought it was under the battery but cant seem to find it. or see it.
Thanks mark