How easy is it to do?

Hi, new guy here. I would like to know how to put new software on a memory card for a Acer PDA. I have bought Tomtom 5.1 off eBay and its on CD. Can connect the PDA to the pc and literally drag and drop the files on to a memory card or do I need a memory card reader to do this?

Also, if for example I have a 256mb SD memory card, and use half of it for the GPS software, can I use the exisiting space to store data, addresses, music etc or do I have to use another memory card?

Thanks,

Ben