intro to tubes

Could some one give me any sites on introduction to tube audio. I'm looking to find answers concerning: What's so great about tubes? How long do tubes last? Are tubes expensive? Are tubes still manufactured(why do i hear so much about vintage tubes)? How are tube amps differet from solid state? What are the benefits? any help would be great. I just think they look cool. I know that newbies in the hobby get shafted on message boards, but please take the time to answer my questions.
I don't know a lot of details on how they work, I just like how they sound. The easiest and cheapest way to get into or hear what tubes do is to try a tubed pre-amp. The tubes only need to be replaced once a year on pre-amps, the tubes are in general cheaper and there is not as much upkeep involved. I am sure other folks will chime in on more details.
I love tubes. About three years ago I went from using Class A Threshold amplification (pre and power) to all tubes. I didn't regret it. The sound is what did it for me. With Martin Logans playing jazz and classical my Sonic Frontiers is excellant. I have not regretted my decision.

As far as maintenance tubes do need to be replaced, which may cost hundreds of dollars. After three years (and about 16 hours a week) I am getting ready to replace my amp tubes, but I think this is dependant on whether you leave your equipment on and how often you listen. I don't leave my equipment on when I am not listening.

Tubes have some drawbacks. Subjectively, the bass is not as well-defined as solid-state. Tubes run hot, so they can burn curious pets and children. They do need to be biased occasionally (a simple procedure). They do need to replaced.

I will probably never go back to solid state. I don't relish the idea of replacing tubes at a cost of ??? dollars, but for me the sound makes it worthwhile. Besides I knew that when I bought the equipment. Good luck!
Yamski, I am new to this site but not new to audio. I make it a point to help the newbies. In answer to your quest for sites to learn, I suggest the following:

This is an introduction to tubes:

This is a nice site for the tube enthusist:

Enjoy the reasurch!
Yamski: You may also want to read through (the tube and SET asylums). I cannot think of any cut and dried answers to your questions, and you will see why after spending some time at these sites. When you get more involved and start selecting specific products, the AA site also has a "complete" word search feature which will help you to locate specific posts on a specific product or subject. Also ask here (at this site) about specific products and general compatiblity issues, when you are ready. Also make am effort to listen to various tube products (as many as possible as most sound different).
Designer bruce rosenblit (?) has several books on tube amps available on his site and from old colony, which is a treasure house of books and parts
Hi Yamski, just a quick note to point out that not all tubed preamps need to be retubed each year. My Audio Research tube preamps (I've owned several) went for 3 and 4 years before I finally broke down and ordered more tubes (preamps tubes are cheap). I didn't keep them on unless I was listening. I now have an ARC tube amp and assume that it will need retubing more frequently, perhaps after a year to a year and a half (at a couple hundred dollars' cost).
I had always been solid state till now, and ADORE the tube sound, at least of the ARC gear. Rich bass, deep velvet midrange and highs. Great!
There's info at tube seller Kevin Deal's commercial website: Go to the main page, click on the "Rare Tubes" button.
This isn't likely to help you out too much, but it should have some entertainment value at the very least. After reading your post, I tried searching the web for suitable information about tube audio equipment and ran a cross this link for an article written in 1972 about the differences between tubes and solid state. Its unlikely to still be applicable to todays SS technology, but its an interesting piece of history. The URL is if you'd like a good late night read (or maybe a sleep aid ;-)).