Loading and Selecting SoundFonts
After acquiring new SoundFont sounds, you will need to load them into your soundcard so your MIDI sequencer can access them. Some sequencers allow you to load SoundFonts right from the sequencer program thus making things very easy. Before you buy a sequencer check to make sure it supports loading and selection of SoundFont sounds. Cakewalk, SONAR and Cubase sequencers work great and other sequencers are now jumping on the bandwagon. If you don't have a sequencer that supports SoundFont loading, you'll need to load your SoundFonts directly into your soundcard or software synth. Consult your manual on how exactly to do this.

Once you're ready to load your SoundFonts, you'll want to make sure to load them into a Bank where no other sounds currently reside. (Unless you're replacing your standard GM set in which case you need to load your new GM set into Bank 0) Therefore you'll most likely start loading your SoundFonts into Bank 1 and on up from there. A typical scenario might be to load "Basses.sf2" into Bank 1, "Keyboards.sf2" into Bank 2, "Guitars.sf2" into Bank 3, etc.

After you've loaded your SoundFonts into their respective Banks you can then use a MIDI program message to access the sounds for each sequencer track. To do this you first send a message telling the synthesizer what Bank the sounds are in and then a message telling the synth what number the particular instrument is stored at. (You can have more than one instrument in a Bank of sounds). For example, if you want to access "Alembic Bass" which is instrument number 3 in Bank 1, you would send the following MIDI message.

MIDI CC 32 - Value 1
MIDI Patch Change - Value 3 

Consult your application manuals for more details on how to do this for your particular synth and sequencer.

Drum Instruments vs Melodic Instruments
There are two types of instruments in a SoundFont file, a "Drum Instrument" and a "Melodic Instrument". The only real difference between them is that Drum Instruments can only be accessed on MIDI Channel 10 whereas Melodic Instruments can only be accessed on MIDI Channels 1-9 and 11-16. Be aware, however, that often drums and percussion soundfonts will be programmed as melodic instruments so they can be utilized on more than just MIDI Channel 10. This is the case with SONiVOX drum soundfonts. If you are not hearing your drum soundfonts on channel 10, simply change the MIDI channel to 1-9 or 11-16. 

Customizing your SoundFont Files
You may at times need to pull certain SoundFont instruments out of a SoundFont file, either into their own SoundFont file or into an existing SoundFont file. If, for example, you are limited on SoundFont memory and only have room for a single violin, but that violin is in a SoundFont file along with violas, cellos and double basses, you'll need to create a SoundFont file with just the violin. 

There are a several ways to do this depending on what software you are using. If you have a Creative Labs card, you should also have their Soundfont Manager Application, which is installed when you installed the software to support the card.

Other applications and SoundFont editors, such as Vienna, have their own methods of doing this. Please consult the manual for your specific application for the details.