I apologise if this has been answered already.  My question is:  I have downloaded Kindle for PC along with some titles.  When I get a Kindle will I be able to transfer them to the Kindle?

Yes. 

Under Your Account, there is a Manage Your Kindle section, and you'll be able to do it from there, or if you get the 3G or have access to WiFi if you get the WiFi one, you can do it from the Kindle, when you get it. 

One caution: When you get the Kindle, try not to download dozens and dozens of books all at once. It really pulls the battery down and then people think the have a defective battery. It indexes each book that is downloaded in order to do the Search function. So when I changed Kindles, I was pretty careful to download only about 10 at a time. 

What's nifty is that it will even synchronize between/among all the devices you are using so that if you've got to Chapter 5 on the Kindle for PC, it will be on Chapter 5 on your Kindle. 

<<download dozens and dozens of books all at once>>

Spoken like a true book lover.  Thank you for your answer.  I wanted to make sure I didn't have to pay twice, although all the titles I DL so far are free.  I'm having great fun.

You're very welcome. 

Oh, it's such great fun that I ended up having to make myself budget. This is on some other threads, but I'll offer it here as well. What works for me is this: I figured out how much I could afford per month. On the first of every month, I buy myself an Amazon GC for that amount. When it's gone, it's gone for the month and that's that. It's helped prevent me from going overboard, and has also freed me to go ahead and buy some of the more expensive non-fiction that I want. It's okay, I really can spend $10-12 for that book I want so much, as long as I've got the balance, because I know on the 1st of the month, I'll have some pocket money again. :-) 

I buy the GC through PBS here, so they get a little bit of credit for it. I'm sure it's not much, but pennies do add up.