You can drill a circular hole in the front of your case using a holesaw. They come in various sizes so just go as close as you can to the size you want. You can then buy a fan grill or something similar just to protect you rfan and ensure nothing gets in the way while its spinning.
The funnel device is roughly something along these lines:
http://i.neoseeker.com/neo_image/146682/article/centuri...
Just something that will direct airflow a bit better than a standard fan by itself.
A fan on the floor probably wouldn't give intake as much air as it would on the front and you have to be careful with dust when you use fans on the bottom of the case since obviously any dust will always settle on the floor of whatever your PC is stood on.
Some fans come with a molex connector which will connect straight to a spare molex plug from your PSU. Others have a connector which needs to be connected to the chassis or system fan header on the motherboard. The trouble with most boards is that they only accomodate for one system fan.
The solution is to 'adapt' a spare molex connector to power your fans. Some people also call it splicing. Basically you cut the connector of a molex plug from your PSU so you have just the wires. You also cut your connector from your fan. Since all you need to run a fan is a +12V and 0V supply you connect the appropiate ends of each cable together. However you have to bear in mind that the colours are different for a molex and 3-pin fan connector:
Molex:
Yellow: +12V
Red: +5V
Black: 0V
3-Pin Fan:
Red: +12V
Yellow: Speed control
Black: 0V
So you connect:
Yellow from the molex end to the red of the fan end.
Black from the molex end to the black of the fan end.
Most molex connectors have two blacks, either will do. Just tape the spare wires up so they don't touch anything.
You have a couple of options for connecting the two ends of the cable. A crimped connection is more electrically sound. You simply strip a length of insulation from your wires and twist the ends you wish to join together. You then insert these into a crimp and clamp down to close the crimp and terminate the connection. You can use a crimping tool to do this or if you don't have one a pair of pliers will probably do the trick. It's a good idea to tape up the crimp also to ensure that everything stays where it should.
You should be able to pick up a pack of crimps from any electrical store. Go for the smallest size and just explain what you need to do. The assisstant etc. should be able to help you if they're worth their job title