Lets break it down.
If you have a PC that can run OptoDataLink, it sure will work. We have a lot of customers that are getting data into a database and onto a web page using just this method.
You have done the right thing reviewing the webinar, lots of practical help there.
The web side, as you say, is the challenge.
My method is to sneak up on it..... its a big ask to just jump right in and try and get the whole site up and running in one hit.
A static page is where I suggest you start. Get the data into the database, then get it out onto a web page.
Ok, sure, you have to hit refresh on the device to get the data to update, but at least you have crossed a few bridges to get there and you have a solid foundation for what comes next........
I think you will find the next step different from what your expecting... the live data is not next... getting a web page to show the data on different devices, if this really is important to you, is a challenge.
The iphone is different from the Android, which is different from the Blackberry. Everything is different from the Blackberry.
Once you get your page showing on all three devices, then it comes time to make it live.
Again, all three devices will use different code (unless you go for some ultra simple layout, or have some development software I am not aware of, you will need three different 'sites' to display the data) to show live data from a 'poller' that is getting the data from the database.
We used Ajax for internetio.com
We also gave up on getting it to work with a Blackberry.
In a nut shell, you are going to make a section of the page (ie, one data tag or point) update without having to update the whole screen.
I do not use anything more fancy than Notepad ++, its a text editor. Granted, most of my pages are very simple, so far we have got away with it.
You have the web page (php, not html), some java to update the elements and some more java/php to get the data out of the database.
At this stage, I don't feel 'comfortable' releasing the code, but it is something that we have in mind.
Certainly, Google can guide you and thats pretty much how we got it working, just looking at snippets and getting it working bit by bit from a static page.
FireFox and Firebug were a big help, as was the error console, also in firebug.
We used Safari to emulate the iphone/itouch (enable developer tools and then set the user agent accordingly) so that we did not need to have one of the actual devices on hand to get the web page going. (The whole Android SDK is needed for just the browser, which is just silly, so we had to use a real device for that one... it was much simpler! No idea what you might use for Blackberry).
Just chip away it and you will get there.