I would like to learn about the different secular Catholic Orders (e.g., Dominicans, Franciscans) and about the Knights of Columbus. How are they perceived by mainstream Catholics and what are the differences among the various orders?
I'm not sure when you say "secular Catholic Orders", in reference to the Dominicans or Franciscans, if you mean those of the Orders who take public vows or if you are referring to the lay, secular, "third orders" associated with them. There is a difference. Most religious orders, such as the Franciscans, do have a lay sub-order if you will, that may, or may not, take private vows, but they do not take public ones and do not wear the Order's habit or live a cloistered life. You can join and remain as a lay Catholic, you just associate with the Order and participate in it's work.
The Knights of Columbus, like all orders of knights associated with the Church, is a fraternal organization. Some orders of Knights are military, some are strictly an individual honorary award, (The Knights of St. Gregory for expl.), some are purely charitable. Most are a mix. They all share a dedication to the defense of the faith, our Holy Church, and to our brother Christians and to those who cannot or will not defend or care for themselves.
I am a long time member of the Knights of Columbus and have enjoyed it immensely. The Order is dedicated to the principles of Charity, Unity, Fraternity and Patriotism. We do everything from distributing wheel chairs to the disabled in third world countries, to distributing Rosaries and Bibles to those who have no access to them.
The highest ideal next to Christ, for a young Catholic man, is that of a noble Knight. A true gentleman. A man of faith and honor. I hope I have been of some help.