Oh well it had to happen in the end, my n900 finally let me down!
Got home last night, no cable TV or internet,, obviously a fault on the network, so I thought I would check online on my n900 and see what the service status page was for the cable company.
Could I get a single web page to load - nope..
Google, bbc, maemo, anything I tried would just time out, even though the signal strength was fine and reporting a 3.5G connection.
The only other time I get this problem is the commute to work on the train, but I always put that down to the handover between masts and the speed the train is travelling at.
Switched to a terminal (one reason why I love my n900) and tried some ping tests, all hosts resolved and I was getting replies. OK, so that proves I have a problem with the browser?
rebooted several times, no difference, which leads to my question. Where can I go to find the log files, or to try and diagnose what is happening on my phone, as I realised last night, I don't have a clue!!
Im not good with linux, though willing to have a root around, and I found /var/log - but there was nothing useful in there, apart from some python logs..
Can someone point me in the right direction for troubleshooting application issues?

Funny enough, it was alright this morning, web pages were working normally, but I would still like to know where to look, so I can try and find out what went wrong.
On a seperate note, I think that last night might have been the first reboot this year for my phone - now that is an impressive indication of just how good or reliable the n900 is

Can you please provide a syslog? See http://wiki.maemo.org/Documentation/.../maemo5/syslog and http://wiki.maemo.org/Documentation/...5#Installation for more information.

If you are not used to Linux, after creating the syslog file you can copy the syslog file to those folders that are visible in the Maemo File Manager by:
* Starting X Terminal
* cp /var/log/syslog /home/user/MyDocs/.documents/
After that you can find the file in the Maemo File Manager by going to Nokia N900 > Documents.

I will install syslog, and see if the problem re-occurs as I have web access at the moment, so I don't think its output would be of any use at the moemnt.
Thanks for the links and for clearing up couple of things for me..