The first question you will be asked is what language to install Linux in. Select English and press Next.
Next you will be asked your keyboard layout. Unless you specifically think your keyboard is different, select Next.
When asked about your mouse you need to make sure you know what type of mouse you have. A PS/2 mouse is a round connector on the back of your computer. Serial mice connectors are bigger and connect to a D-shaped socket with 9 pins that looks similar to your monitor connector. A USB mouse would fit in a basically flat thin rectangular hole.
If you change the default and put something other than your real mouse your X server might not work properly.
After selecting your mouse Press Next to install, then select Custom System and press Next.