T-SQL In Mngmt Studio Express Doesnt Affect Change- Obvious Omission?

I must be doing some daft thing-
In Management Studio Express I have Northwind, Pubs and a db of my
own.
I can create SQL select queries and get results back fine but when I
try to do an insert, update or delete I get the message: (1 row(s)
affected) - making me think all has gone well, however, when I refresh
and look at the relevant table nothing has changed.
Any tips?

ps In learning the basics of SQL server, vs.net, javascript and
vbscript I am often encoutnering a problem that halts me for five
hours or so but has an obvious solution 'if you know how'- I suppose
this is the difference learning on your own vs in an office
environment- "Pete, how do you...?". I am trying to create a
beneficial application under my own steam and with limited resources-
are there any other sources of internet support I might not know about
but could use to get quick answers to sticky techie questions?
D