OK, I read this entire thread, and there are others like it; and, there are varying views from you guys who know your stuff.
As another newbie, I've been doing a little reading, and in addition to this forum, a friend advised me to decide first the purpose of the weapon: home defense? Sport? Then, he asked me whether I'm going to use it often for target practice. Furthermore, he asked me to consider the cost of ammunition,
So far, so good.
and finally, whether I will keep it loaded.
The gun won't do you much good if it is not loaded.
He said a revolver is good for self-defense and very easy to use for beginners,
First part is right on. Second part is not. Revolvers require greater skill than semis, generally speaking. That said, they are still the best choice overall in terms of reliability. There are few things in life you want to happen less than have your gun malfunction when your bacon is on the line. I have several semiauto pistols, but I carry a highly tweaked 686 everywhere I go. It is my weapon of choice.
but he also said that for home defense, a .40 or .45 semi-automatic pistol would be better than a revolver because it has more rounds -
Faulty reasoning. When you get your pistol, the smartest thing you will ever do with it is get your hide to the range, learn safe handling, and then marksmanship. When someone is in your house at 2AM uninvited, you will be shitting large anvils. If you do not know which end of the gun the bullet comes out, you will be tempting fate. DON'T DO IT. Train yourself because even with a goodly amount of training you will be sweating masonry nails.
When your skills are well developed, you will not likely need more than 6 rounds. If you do, you may in more trouble than you can handle and in that case 1000 rounds may not be enough. Don't go for the high capacity bullshit, because that is all it is. Those guns were designed for two purposes, the first being for use in actual open combat (warfare) and the other for stupid, lazy cops and their stupid, stingy departments that no longer train them well in marksmanship. A 20-round mag is all nice and well, but if you cannot hit the broad side of a barn all the ammo under heaven isn't going to help you a bit.
and, if I do not plan on keeping it loaded, the semi-auto would be a better choice.
Not sure about the reasoning. Will you carry the gun?
I plan on taking a gun safety course as well as going to a range to try some handguns.
Good thinking.
I've read good things about the following: Glock, S&W, and Colt; and, my friend said he does not recommend the Taurus.
By us we're fond of saying that Glocks are fine as long as you don't intend on hitting anything you're shooting at.
I would check out a S&W revolver. If you buy one, take it immediately to a GOOD gunsmith and have him go through it, especially have the trigger tuned and a lighter hammer spring installed. The latter is, IMO, important in helping you develop good double-action shooting skill.
If you're not carrying, I would recommend a large-frame S&W. I carry a K-frame, which is very large, but I am used to it and I don't care if some peoples' eyes bug out of their heads when they see the huge bulge on my hip. They can get over it or get bent.
Smith makes a very nice, though pricey, large-frame, 8-shot revolver with an aluminum frame - it is all black and for the life of me I cannot recall the model. It is a very nice revolver IMO and after a standard tuning would make a fine gun for carry.
If perchance your weapon is for home-defense only, I would recommend a shotgun. New ENgland Arms makes an 870 clone in 12 ga. that is excellent and not terribly expensive - about $250 last I looked (about 2 years ago). Steel receiver, 20" barrel, 6 round capacity, cylinder bore - you really cannot go wrong there. Made in China, but so it just about everything else anymore, so be practical. I have one and it has been extremely reliable and that is the watchword in the game of self defense. Don't be fancy - be RELIABLE. A fancy gun isn't going to mean much to you when you are dead.