Welcome to the Fold!!
First; off you need to separate the people with the minority issues from the overall body of users. A b it of back ground is in order here to help you understand the issues. I run Linux on my desktop machines and have so for some time, my last Mac being a Mac Plus. A couple of weeks ago (month) I went out and purchased a new Mac Book Pro so my experience with this version of UNIX is new.
Deep down that is what OS/X is, it is a version of Unix with NeXT Step (Cocoa) on top of it for a user environment. That is a pretty solid combination! Like all things software though bugs do creep in from time to time, but my experience so far is that 10.5.2 is very stable. I especially like how easy it is to add in the assorted UNIX programs and to manage other free ware apps.
It is not all about free ware either as the reason I went with Apple was to partake in some of their class leading software. This being Aperture, XCode and iTunes. Maybe some others in the future. In any event see some comments below.

I hear a lot of annoyances with Leopard on this website. I hope I don't experience any of them. This is my first mac (my reason for buying was Apple's innovation, the rock solidness of Tiger, and the nice additions in Leopard).
While those are all good reasons to go the Apple route I would suggest that taking in the bigger picture is just as important. By this I mean it is good to have competition with Microsoft. It is pretty obvious what happens to a monopoly when the leadership team doesn't have a vision anymore. In other words alternatives like Apple, Sony {PS3}, and Linux are very important to have when the big ship is sinking.
I ordered it yesterday through macmall, it shipped yesterday and by the tracking ticket - it should be here today or Monday. Please let me be a happy mac owner!!

It is entirely up to you. The best way to do so is to develop the back bone to not let people crap on your vision of the world.
I am really sick of Windows. WIN 98 second edition and XP professional were the best operating systems from MS. All the others I have not been happy with as there were too many problems and comapitibility issues. I did not dare to try vista. Many Many people I know upgraded to it or bought new computers and are sorry they did and are looking where they can buy XP disks.
There are actually people out there that will tell you they like Vista or for that matter any previous version of Windows. The big draw for Windows has always been the notion of software availability which is real. In the past I simply could not have done my Job on a Mac system so at work it has always been Windows in one variant or another. It can be a place to get work done reliably in a tightly controlled environment.
The good thing with the current Macs is that you have a very stable OS that runs on Intel hardware and thus can support Windows in various ways. So when using todays hardware a Mac does not completely exclude you from the world of Windows software.
Can any one tell me if these updates are required or optional? One thing I hate about MS is waking up in the morning to find that updates were downloaded and then spend 1/2 my day fixing the errors that are occuring.
You should normally consider updates as required!!! That is after verifying that they cause no trouble. Many of the problems in Windows for example result from people ignoring system and security updates.
In any event I've already have gone through various updates and have had no problems.
Also, I probably may not connect my MAC to the internet (atleast not yet) I have heard that while Mac viruses are few and far between, Windows viruses still get downloaded to your MAC.
Some will some won't. That is no reason to avoid the internet though. First; off there are very few cross platform viruses. Second; a huge portion of Windows viruses come in E-Mails and exploit issues with Windows Outlook.
While they can't do anything - they clog up your hard drive and eat disk space.
No more than any other bits of software that gets cached on your hard drive. The approach here is simple manage what is cached on your hard drive. Thus limit how much space Safari or FireFox use on your disk drive. Same thing for your E-Mail programs. When it comes to downloads manage the also. Make it a point to trim your downloads directory often.
Can anyone recommend a good virus protection, adware and bot removal tools for the mac? I would not want that junk clogging it up - should I connect to the internet.
I don't have such and really don't see a pressing need. Certainly I will need some sort of anti virus protection in the future. Thankfully though I haven't experienced much in the way of adware getting installed.
In any event I'm bothered by the impression you give that you have no control over what gets installed. You do and that goes a long way to making the machine stable. As to the adware, antivirus and other "protection" you want to install, realize that that stuff eats up a lot of CPU cycles and goes to making a sluggish computer. Certainty all the junk ware of Windows doesn't help the impression of performance but full time virus protection, and other utilities are are a contributing factor. There is not free lunch when it comes to virus protection.
Finally What does get downloaded to a Mac only clogs it up in the sense of using space on the hard disk. Just because the programs are on disk does not mean that they are executing in back ground eating CPU cycles. My suggestion is to put more effort into learning about your system and how to use it properly. Buy a good book or two or find some credible internet references. Knowing when and how to do the right thing can lead to a much more reliable computer.
Otherwise you can spend your hard earned money with a "computer repairman".. Most of which just reinstall the system software to fix mucked up systems.
Dave