I'm going to presume that you have a tower or case that is the correct size.
First clean out the case of any junk, dust, etc. Then ground yourself to the case so as to dissipate any static electricity. I suggest you get a static clip for this.
Remove the motherboard from the static free film bag and locate the screw set bag. Most of the screws for ATX and Micro-ATX boards are standardized so it really doesn't matter which screws you use out of the bag. The vast majority of them should have a multi-head (phillips, flat, hex). Take the motherboard and gently place it in the case, making sure the case is on it's "back" so that the side you're mounting the motherboard to is flat on the ground.
Align the screw holes of the motherboard with the best fit of the screw holes found on the case. Note: If it is an intel based processor motherboard, you may need to mount the processor first and then the heat sync and fan before mounting it to the case, as it mounts directly to the motherboard. Since the Foxconn 761mx is an AMD board, this shouldn't be an issue.
Then locate your peripheral components (hard drive, optical drive, fans, heat sync, processor, ram, case fans, video card etc). Mount the AMD processor into the AM2 socket, making sure the socket handle is up or in the unlocked position. Once it is seated lock the processor into the socket by placing the handle down. Be firm but gentle in pushing the arm down. It should lock in smoothly, if you feel any major resistance, stop, release the handle and check to make sure the processor is in place correctly.
Once the processor is installed, cover the base of your heat sync with heat gel (Thermal Compound)(if it doesn't already have it, I suggest Arctic Silver~ http://www.newegg.com/Product/Product.aspx?Item=N82E16835100007
~ as it is superior than most of the preloaded gels).
Because this is an AM2 socket with a specialized clip, you'll find that it can be a little persnickety getting it on. The heat sync you have should tell you how to do it. If I remember correctly this particular clip you unscrew and loosen the side clips. The heat sync fits under this type and you then clamp it down. But I'm going off of a picture so I'm not exactly sure.
Once the heat sync is mounted and pressed firmly against your processor you're ready to situate your other components. Install your ram (making sure to match the notches to the spacer. This motherboard uses DDR2 ram so it's not that fast, but you have two slots to fill up to a max of 16 gb). Place your hard drives or SSDs into the drive bay where you'd like them to be, and place the optical drive into the optical drive bay. If you're going to install a zip drive or floppy drive (first why?) connect it to the black IDE connector. The primary hard drive on this motherboard can be either SATA or IDE. You can get SATA to IDE adapters if you need to have more than one SATA hard drive, or you can purchase a PCI-E SATA controller to expand the hard drive space.
Mount your video card in the PCI-Express X16 slot (the long yellow slot) and then mount your power supply in the specified space in the case. Finally mount your case fans. Usually one in the back below the power supply (if it's an upright case) and one in the front near the hard drive bay.
The power supply will have four screws (probably already in the case) that will hold it into place.
Now that all of your components are seated or mounted, it's time to connect the power supply to the components.
First locate the ATX power lead. This is pretty self explanatory. This will either be 12 by 2 or 8 by 2+ 2 by 2, or 12 by 2+2 by 2 connector that fits the main power connector on the motherboard, located next to the two ram slots. You'll find a 2 by 2 power port next to the processor slot. Seat both power power connections on the board.
On this board there are two power input only. The remainder of the power output goes to the hard drives or ssd, the optical drive, fans and heat sync, and possibly video card or other expansion cards. If you've installed legacy equipment (non-sata or IDE hardware) you'll have a large white four prong male plug that will fit tightly into a four prong female plug on the legacy equipment.
Where as if you're working purely with SATA devices, you'll have a flat power supply plug that is keyed (looks like an L) that fits into the smaller power supply plug found most often to the left of the main SATA port on the hardware. This plug will be larger than the SATA plug in width, but thinner in height.
The IDE port and 10 pin IDE port for the legacy hard drive and floppy drive on this motherboard sit next to the main power plug, while the SATA ports are the Two Blue L shaped plugs. The IDE port is blue while the 10 pin IDE port (for the floppy) is black with a lower left hand missing pin (keyed).
Connect your hardware to their respective ports.
Next locate the 8 pin plugs for the Case USB ports labeled USB1 and USB2, usually for the front. Most cases come with a front USB expansion port. This will attach to one of the 8 pin connection points on the motherboard. Some older cases come with firewire or extra usb expansion cables which can be attached to either USB pin plug. USB1 and USB2 ports are painted green on the motherboard.
You'll find on this motherboard four more plugs, one that looks like a very small black four pin port near your cmos battery, a four pin port that has no plastic around it labeled COM2 with a blue underlay painted on the board. A black painted 7 pin plug near the 4 pin black port and then another 4 pin plug point labeled speaker.
If you want to have a case speaker installed for use with beep codes (a set of CMOS codes that will beep if there is hardware failure) plug the speaker into this port (note: most new cases don't come with this speaker and to acquire one you should check with any second hand computer repair company). The 7 pin black pin plug is where you connect your power and reset button and power on light. The 4 pin port near the Cmos battery is for audio exchange. While most new SATA optical drives run audio through the SATA controller some legacy optical drives that are IDE need to be connected to the onboard audio using a 4 pin cable. COM2 is rarely used, but can be used for other controls, it works as a port extension. Many new motherboards don't have these because everything has gone USB and the old serial port standard isn't used anymore.
That is a complete guide to putting together your computer.