As long as you do not web surf from the server you do not need much protection, but it would not hurt to install virus protection. There are some that are free and will install on Windows servers, just look.
I am more concerned whether you can really run a server from your home, and if you realize the full implications. For 4 years I also ran a web server from my home office to save money. I had DSL, and my ISP did not block servers as most do now. That is your first hurdle: does your ISP block servers?
I got my server set up fairly easily and switched over, but then the fun began. I quickly found out that even though the web server was using my upload bandwidth, sometimes my web browsing came to a crawl. You see, a TCP connection to download web pages requires small acknowledgments to be sent back to keep the connection flowing. So, when my web server was busy and using all my upload bandwidth, my acknowledgement messages would be dropped, slowing my download to a crawl even through I had plenty of download bandwidth available.
The solution was to throttle my web server to about 90% of my upload bandwidth, and everything worked fine.