Should i go for ubuntu 64bit or 32bit?

Federico Tello Gentile suggests this article as an answer to your question:
FAQ #1232: “Choosing Between 32 and 64 bit Ubuntu”.

What's the main use of the system?

getting to know linux threw the terminal, internet, open office spreadsheet and word, stellarium, downloading, intensive use
the faw tells me to go for 64bit unless i got a specific reason to do go for 32 bit

are there any down sides on 64bit?

Hi: I am using the ubuntu 10.04 lts 64 Bit on an desktop intel duel core 3ghz with only 2 gig ram @ 667mhz
and it works very well for what i do as a home user / home office etc.ethernet connection for internet.
make sure you install from the software centre " ubuntu -restricted-extras."

Hope it helps you in some way
Regards
Barry
Australia.

The 32bit will be fine, Your use will not benefit from 64bit. If you were using computationally taxing stuff like music encoding / video editing etc then 64bit can help but your basic use leans more towards 32bit. Also 32bit is still better supported then 64bit but it's getting better

in many case, using 32 biis always beneficial
simply because
it support more software and has less compatibility issues

if you are new to Ubuntu to have less software incompatibilty and trouble, use 32 bits...