The promo thing is a long and epic way

where i had to go through once as well.
And today im getting so many promos each week that i sometimes cant check them all
Anyways the first thing u should know about promos is that each label, or artist only gives them to u if u give them something back. And this is feedback! So u need to play in a club or at a radio else u wont stand a chance about getting anything for free. As bigger the club as better it is.
So the first thing u should do is contact labels, artists... tell them that u play at a club ... with Flyer or contract for instance and tell them that they can send u some promo stuff. At the beginning u wont have much luck since u are very unknown! Sometimes it helps as well to send them some promo mixes of yourself so they can see what kind of music u play. If u got a forum with feedback of your "fans" tell them it can also raise your chance.
Also try to build up contacts with producers! Try to contact new or upcoming producers since u got a better chance with them. Also if u spin together with some at an event talk to them and u might get some stuff.....
Always build up connections and keep in touch with them.
A second way which i cant recommend though is the way about promo agency´s. A lot of Agency´s send u each week a package with Vinyl or Cd´s for a small fee around 50 euro the month.... But dont expect stuff of Tiesto, Armin, Signum .... in there. U will prolly get a lot of commercial stuff or tracks from rather unknown producers. Which aint must be bad though it could probably disappoint u after a while since u prolly hope for the big Artists
Though i did start so as well

.....
A third way is to become a charts maker. There u apply to a list like the DDC and of them u will get each week different kind of tunes. U need to rate them in a list and send them back the list. The tunes u can keep of course. The list helps the company to create the charts like for House, Trance ....
Though to get in the list is hard since many other people apply there daily. Though its sure worth a try.
So now its about you to decide
take the easy way with an agency or the hard one and build up contacts
whatever u do good luck