Generally, the best man acts as the toastmaster, and prepares a list of the order in which each person will make a toast. There is an established protocol which the couple may or may not choose to follow.
Microphones: You may want to check with the hired musicians for the use of their microphone if the rehearsal or reception is in a very large area and people may have a hard time hearing. You might also consider if the sound system will be set up when you need to speak.
Special Considerations: If you, or someone else, will not be able to stand as you deliver your toast, you may want to make special arrangements ahead of time to move to a location where you will be seen by all.
Rehearsal Dinner
You might follow this order:
The best man toasts the bride
The bride toasts the groom
The groom toasts the bride's mother
The bride's father may toast the groom's parents
During the Reception
You might follow this order:
The best man toasts the bride and groom
The groom toasts the bride and her family
The two fathers toast the bride and groom
The bride and groom toast each other
Tips for that Perfect Toast
Don't be long-winded.
Stand to give a toast; remain seated to receive one.
Prepare ahead of time; know what you are going to say.
Mention those you are toasting by name, your relationship to them, and a thought about this wonderful event.
Add witty anecdotes wherever possible, if they are in good taste.
Speak slowly and loudly enough for all guests to hear.
You may want to avoid consuming alcohol before your toast.
Don't forget to cap off the toast with a hearty ending like "Cheers!"