TS Web Access?

I am trying to help a buddy of mine who is a small business owner set up a Windows 2008 Server at his place of business. He has a few employees that work for him at his CPA firm that travel quite a bit and need to access application(s) remotely on the server. I have never configured TS Web Access before and it would be great if any of you could help a brother out. What needs to happen apparently is that the employees will need to gain access to my buddy's website from their laptops, click on either a link or an application icon that then runs an application like Quick Books remotely on the 2008 Terminal Server over a secured connection. My buddy has a static IP set up with the ISP so that is taken care of and his website is up and functional. He uses DSL in his office and a wireless router is connected to that. I have configured the DSL modem and his wireless router and set up his server which is a PowerEdge T100 with a reserved IP. The DSL modem is also configured as the acting DHCP server in this environment and uses PPoE to connect and authenticate to the ISP. I did not upgrade the server to an AD DC since it is not some large corporate environment, not even a mid size corporate environment. In fact, it is just him in the office and his employees just work from home and there is only around 3 or 4 of them. IIS 7 is running on the server also and I do not have extensive knowledge regarding this technology. My buddy initially had a consulting company attempt to set this up for him but the company was sitting on the job for 6 months or so without really doing much at all and so he just cancelled the account and got his server back from them. He then called me up and I said I would take a look at it and try and configure to the best of my ability. He is a good guy and I just want to help him out so he can have a productive little business. Going over the Invoice from the consulting  company it shows that the SSL certificates were already ordered and I found those located on the server in a directory on a separate drive. Also on the Invoice it reads "Starting work on TS Remote Apps but need to get list from 'my buddy' and get proper SKU for a pair of retail Win Server 2008 RDS CALs." Apparently the CALs were never ordered since he cancelled the service with the consulting company and this is where I am at right now. Let me recap here about what my buddy wants to happen again:

1. Have employees access the public website from home or anywhere on their portable systems
2. Click on perhaps a Quick Books icon on the website that will open a secured session to the internal PowerEdge T100 (Windows Server 2008  Standard with Service Pack 2) in his office to run the QB application installed on the server.

Just so you don't think I am being lazy and trying to piggyback off of your knowledge, I am researching all this right now on the following sites:
- http://www.microsoft.com/windowsserver2008/en/us/rds-product-licensing.aspx 
- http://technet.microsoft.com/en-us/library/cc771623.aspx

Thanks everyone. As always, I appreciate your help.