Raspi + External HDD Recommendations

[Lanzelet]

Hi,

I am wondering which solution is the best for my Raspberry Pi Media-Server Setup.

I have a Raspberry Pi Model B running with Xbian. It's attached via LAN to my Access Point (Asus N56U) and via HDMI to my TV. Currently I am streaming Movies from my Windows 8.1 Laptop (WiFi), which works quite well. But I want to switch to a 2GB External HDD, where all my Movies will be stored.

But how should I integrate the HDD in the network, so that I can easily add new stuff on it via my Laptop and I am not have to plug it out and in all the time?

Should I plug it in to the Raspberry-USB-Port? Then how can I save new files to the HDD from my laptop?
Or should I plug it to my Access Point and save new files via WLAN?

I don't want to buy new hardware in the near future.