Displaying Taxes and Viewing Invoice of Orders

I am in the finishing process of my website and need to tie up a couple loose ends. First: For some reason, my tax module isn't showing the taxes in checkout. For example, an item is $19.99, it should add the tax and have a total of $21.98. Instead, it's coming up as $19.99 the entire time. I know this is a simple fix, I just can't figure it out. Second: When items are purchased, I'm not able to see the invoice in my administration panel for some reason. I think it's because after paying for the item through PayPal, the link that goes back to the site doesn't go to the finalized checkout area, instead, it goes to the login area...I'm sure their's just a linking problem that needs to be fixed. I look forward to your bid and can't wait to get this started and finished! =)