Maintaining my 75 gallon tank

Question
I have watched and read many articles on 'maintaining your aquarium'.  But I have a few really basic questions that have not been addressed in these articles.  First, my tank is a 75 gallon and I currently have 5 tetra, 3 algae eaters, 1 gourami, 1 male betta and 2 comet goldfish and 2 fancy goldfish.  I bought the goldfish in the beginning because I had read that they help with the cycling.  I have a Penguin 350 filter.  When I am ready to do the water change outs on my tank do I need to remove all of my fish when vacuuming the gravel?  If so, do I need another aquarium and all of the accessories, heater, filter, etc to keep the fish safe in?  If I remove 25% of my water for maintenance reasons what is the best way to bring the water that will go back into the aquarium to the right temperature?  If using 5 gallon buckets how long do I need to let the water sit before returning it to the aquarium?Will I need to put a heater in to bring to the 75 degrees my tank is currently at?  I feel rather dumb asking these questions, but I want to make sure my fish stay healthy and stress free and that I can perform these change outs as quickly as possible and get my fish back into a clean home.  So any answers you could give me would be great. Thank you

Answer
Hi Cindy,
These arent dumb questions :).  First off I do want to point out something.  You have both tropical fish and cold-water fish (goldfish).  Tropicals require heaters and goldfish do not, unless its winter time and etc.  Since you have both types, you must keep the water in the middle to keep both fish satisfied.  Tropicals require 75F-80F and goldfish require 65F-72F so I would say to keep it around 73F-74F.  

When you do a water change, you do not need to remove the fish.  The fish will just swim away on their own.  15%-20% water changes must be done once every week to keep the nitrogen levels down.  When you add new water to the tank, you dont need to make it the same temperature before adding.  But you must remember to condition the water before adding to remove the chlorine and choramine.    

The only accessories you need is a heater and filter.  Lights is not of  a big importance unless you are keep live plants which is on a whole new topic.  
-Matt-