Do you feel strongly about having a SFH? A condo or even a townhouse might be a nice first step into home ownership. You would be building equity, but have a lot less maintenance than you would with a SFH. Especially a fixer upper, which you might tend to find in your price range.
Anyway, if you do feel strongly about a SFH I would urge you to consider location first. I'm guessing you would rather spend more time with your infant instead of commuting to/from work. So I would narrow in on neighborhoods first to minimize your commute and then see what housing options are available there. You might also want to consider the schools in the area. If not for your child, but it will also help with resell again later.
Based on what you've described so far, I'd look for a little cottage or bungalow or cape cod that meets your functional needs (1 vs. 2 bedroom?, etc.). And then spend some time to add the features that you like -- wainscoting, shutters, etc.
Also, be prepared to make compromises. It's a tough market right now - so decide what is *really* important to you.
Would this appeal to you?
http://www.redfin.com/VA/Arlington/2120-N-Quebec-St-22207/home/11232945
Some examples of what has already sold:
http://www.redfin.com/VA/Arlington/2000-N-Culpeper-St-22207/home/11236280
http://www.redfin.com/VA/Arlington/5505-4th-St-S-22204/home/11258705
Good luck, OP. Come back with more questions!