Good 1st level modules

[TheYeti1775]

B1 In Search of the Unknown

T1 Village of Hommlet

U1 Sinister Secret of Saltmarsh

available cheap as pdfs from most places...

I concur with Diaglo on this one.
Use T1, if you want the base for a long term campaign. You can pick up the full T1-4 Temple of Elemental Evil as a cheap PDF file. I have both the Module (one of the original 'supermodules' of the time) and the PDF. If your running 3.5, go over to the downloads section and grab the conversion doc. With a few minor adjustments, it runs great for beginnners.

Also the freebie from WOTC The Burning Plague is a good one as well for an introductry, as a prior to T1. Could even tie in using the BBEG as really a TOEE cultie priest.

Yeti

 

[Matchstick]

Of Sound Mind

I think that's my favorite. Gorgoldand's Gauntlet is good as well. I think the first module I ever played was "Village of Hommlet" so I have a soft spot for that one as well.

In general I'd say Dungeon might be the best place to find a good selection.