This a link for a hostel in Palermo Viejo that is owned by a women and might be of interest to you. It is cheap and pretty nice place, but for a single female traveling might prove a good choice
http://www.casajardinba.com.ar/english.html

Here are a couple good links for information about Palermo Viejo, SoHo/Hollywood
http://trendypalermoviejo.blogspot.com/
http://www.palermohollywood.net/

For dining Bar 6 (lunch) -Armenia 1676, Olsen's (for Sunday Brunch) -Gorriti 5870, Sudestada -Guatemala 5602, El Trapiche (old world great food, a must) Paraguay 5599, Juana M, -Carlos Pellegrini 1535, and the cafe at the MALBA is a great place for an afternoon coffee or lite lunch. If you want something a bit more upscale then head to the Bo Bo (Bo Bo Hotel) Guatemala 4882 y Thames Tel: 4774-0505. Food is outstanding.

A couple other places to take a look at that are fairly cheap hotels
Che LuLu http://www.luluguesthouse.com/ and
The Hotel Costa Rica http://www.hotelcostarica.com.ar/eng/

Also, once you arrive at EZE do not, repeat DO NOT use the money exchange located at baggage claim. Nothing short of thieves they are. Wait until you are in the arrivals hall and you will find ATM's and a bank that offers much better rates.

Suerte
SAM