Read the contract - thoroughly! If they won't give you a contract, forget the deal, unless you're willing to work for free. Also make sure it is a non-exclusive deal, otherwise you won't be able to use your tracks ever again, if your track gets big, you'd be pissed that you can't release it yourself on an album later.
The good stuff about working with labels, particularly the bigger ones is the publicity, but they often tend to cut you a raw deal. Use them to get your name out there if you're unknown. I've worked with many fairly substantial labels & producers etc in my time. Most recently I've been working on Electro-Funk under the moniker 'LektroiD', I was signed to various labels, such as Dominance Electricity (Germany), Binalog Productions (Athens), and Street Sounds (UK). I also remixed a number 1 hit from the '80s. I've set my own label up now and released an album on iTunes, Amazon, Bandcamp etc, which did surprisingly well, but I have a feeling that was mainly due to all the publicity I'd got in the scene from being published on other labels.
Bandcamp is great if you want to get your tunes out fast and instant returns, iTunes Amazon etc is a slower turnaround, and takes about a fortnight to get your tunes up, but more widespread. I use Bandcamp for all my pre-release stuff.