A few nice hp photo images I found:
HP ProLiant N36L mainboard
Image by uıɐɾ ʞ ʇɐɯɐs
The Hewlett-Packard Proliant N36L mainboard is a small affair, but remains expandable. The expansion capabilities (mouseover the photo to see notes):
● PCIe x1 slot, PCIe x16 slot
● Internal USB 2.0 port
● SATA port
● Two DDR3 DIMM slots
If I had to list some complaints with the design:
● The eSATA port faces outwards: it's not straightforward to reuse this port for an internal disk
● There is a PCIe x4 slot next to the x1, presumably for use with HP's proprietary management card. It's useless for anything else. I rather have had the placement reversed, i.e. the PCIe x4 facing outward so it were usable
● Not depicted in this photo: there is very little clearance for RAM. You need to use low-profile RAM without heatspreaders, otherwise it'll bump up against the case's drive rack.
If you're looking for more information, I've both a hardware review and software review of the N36L.
HP-Marathon-Photo
Image by peirunman