I used this guide http://library.linode.com/networking/openvpn/ubuntu-10.04-lucid

to setup my vpn. I ran all the commands on my linode with root access, copied relavent files to my client and setup tunnelblick. When I use tunnelblick it's successful in connecting to the vpn.

After that, i can ping my linode ip and 10.8.0.1 but nothing else else seems to work. I can't ping www.google.com for example and i can't browse any websites.

Where can I look to start trouble shooting what's going on? I made sure to do the iptables part of the openvpn setup as well as installing dnsmasq. But I still can't browse any websites.

my particular problem was that i had specified ip's for my DNS in network settings. once i deleted them and reconnected to the VPN it pushed down DNS settings to use (DNS Server = 10.8.0.1, Search Domains = openvpn)

i just got lucky trying different things out and figured it out. but one thing that helped was looking at the log files. the relevant files are

/etc/openvpn/openvpn-status.log
/etc/openvpn/openvpn.log

by default openvpn will put logs in
/var/log/syslog

but i changed my /etc/openvpn/server.conf so the log would goto openvpn.log instead

hope this helps someone else out there.