I personally use dyndns to do this. The idea is that you need an address that is propagated through the domain name servers out in the world and there are services to do this kind of thing. Go to dyndns web site and take a look around. Here is a reasonably easy to read article that can help:
http://www.makeuseof.com/tag/connect-home-network-dyndns/There's a couple of gotcha's though. Your internet provider may well change your ip address at home without notice. Mine used to do it twice a day on average, usually around 8PM. This means you have to 'publish' your ip again to be sure that the dyndns service has the correct values. You do this by sampling your externally visible ip address a couple of times and hour or so, and if it has changed, do the publish thing to get the value corrected.
If you don't need a name on the DNS servers, you can actually just get your ip by going to
http://checkip.dyndns.com/ which will return your address and then you type it into the URL line of your browser; just like when you're configuring your DSL modem.
I hope some of this makes sense to you