Buying IPAD Today 16g or 32g..ADVICE PLEASE

Hi and Happy New Year.

The 16 GB will probably serve you very well considering your planned usage.

You can always sync materials back and forth with your computer if you start pushing the storage limits.

I have gotten by very well since August with 16 GB.

You have a lot of options, Safari does pdf files, iBooks will read pdf files, and you can check the apps store for apps that run independently. I am sure others will jump in here on the subject of pdfs with a lot of other suggestions and ideas.

iPads do pdfs very well.

horsegoer,
(Short answer) Welcome. If you're just going to read PDF's, your new iPad will do that without any additional software. Like Ralph pointed out, there are several solutions built into the iPad. iBooks is quickly becoming a better solution without having to purchase a third party app if you only want to read PDF's. With the recent update, you can now create collections to make sorting and find your PDF's easier. With the size of your PDF's being so small, you can keep hundreds on the device along with your music.
(Long answer) If you find you want to eventually fill in, mark up, or draw on your PDF's there are several great solutions available. I use Form Tools PDF because I have several forms I fill out repeatedly and this allows me to fill the form out, save it, and then pull up a blank form ready to fill out again. I can also draw on, hight light, and sign my PDF's with this app.
On a personal note, keep one thing in mind, once you find how productive you can become with the iPad, you may want to keep more and more things on it. I bought the 64GB model because I wanted to keep a bunch of work documents and reference material on mine, and I have only 4.8GB of room left. Additionally, I've only needed to print two (2) pieces of paper since getting my iPad on April 3rd and those were for DMV. But like I said, it's a personal thing. I just want others to know that if you understand the functional limitations of the iPad, and how to work around them, this device can not only replace a laptop for your day to day computing, but it's a fantastic business tool. I've used mine daily since getting it and my colleagues are amazed by the iPad's capabilities, and it's only getting better.
PS Don't be surprised if the iPad starts making you sound like a Mac fanboy 🙂

For your purposes, the 16Gb should be just fine. There are plenty of cloud storage solutions that will enable you to save items online and only download them to the iPad if/when necessary.

I have a 16 Gb iPad with ~200 songs, ~100 pdf files, tons of apps, and ~1000 photos, and it's barely 1/2 full. I use it routinely to write documents with Pages and manage a number of spreadsheets in Numbers. I keep items I don't need immediate access to on Dropbox for rapid retrieval if necessary.