Produce work. A DJ who has a large volume of mixes, sets, remixes and original tracks is more attractive than one who does not. Continue to perfect the craft of DJing and improving skill. Book as many gigs as possible. Contact club owners, promoters and send them mixes and samples to help book gigs. Network with people in the music industry by attending events and parties to increase exposure. Always promote and make links to your website, Myspace page and other social networks highly visible. This increases your visibility and popularity; helps achieve more bookings and fans; and creates a brand that is more likely to get signed.
Contact record labels and managers. Send them samples of mixes, remixes and a portfolio of work. If the your original production was downloaded 12,000 times mention this. Find record labels and managers by researching professional DJs. Look to see what label they are assigned to and who manages their bookings. Contact those people. It can be difficult to get a foot in the door which is why knowing the right people is so important.
Connect with other DJs. Go to their events, see what they are doing and form a network of DJs. All of these DJs are likely trying to achieve the same goals. It is helpful to talk shop with them and find out what they are doing, who they know and see if an introduction to industry contacts can be made.