IMHO the best bet is to listen to some bachata songs and translate the lyrics. Learning to sing the songs will help your cadence and accent. Keep in mind that many songs are a bit slangy and the grammar isn't always perfect.
Dominican Spanish is one of the harder variations, but if you can understand it, Columbian and Argentinian Spanish will be easy. Watching telenovelas can also help, but try to watch Columbian more than Mexican. The Spanish in the Columbian is usually closer to "standard" Spanish. Puerto Rican Spanish is prob the hardest because of the corruption from learning English as well.
Example:
Raulin Rodriguez-Esperame - YouTube
Esp?rame-- Raulin Rodriguez
Si yo pudiera volar -- if I could fly
Ya estar?a contigo mujer-- I would already be with you woman
Hoy me doy cuenta que no puedo vivir -- today I realized that I can't live
Sin tu amor-- without your love
Novia m?a, esp?rame-- Girlfriend mine, wait for me
D?as que vienen y van -- Days that come and go
Esperando mi regreso mujer-- waiting for my return woman
No te preocupes que los a?os pasaran --don't worry that the years pass by
Y volver? --and I will return
Y sabes volver?-- and you know I will return
Ayer me puse a llorar -- Yesterday it made me cry
Cuando me lea tu carta mujer-- when I read your letter woman
Y me dec?a cansada de esperar -- and you said you were tired of waiting
Hoy me encuentro -- and now I find
Y no s? -- and I don't know
Que voy hacer--what I'm going to do
Esp?rame porque yo volver?-- Wait for me, because I will return
Tarde o temprano all? estar?-- sooner or later, I will be there
Esp?rame porque yo te quiero-- wait for me because I want you
Porque me muero porque no puedo vivir sin ti-- Because it kills me because I can't live without you..
Esp?rame porque yo te quiero
porque me muero porque no puedo vivir sin ti
D?as que vienen y van
Esperando mi regreso mujer
No te preocupes que los a?os pasaran
Y volver?
Y sabes volver?
Ayer me puse a llorar
Cuando me lea tu carta mujer
Y me dec?a cansada de esperar
Hoy me encuentro
Y no s?
Que voy hacer
Esp?rame porque yo volver?
Tarde o temprano all? estar?
Esp?rame porque yo te quiero
Porque me muero porque no puedo vivir sin ti
Esp?rame porque yo te quiero
porque me muero porque no puedo vivir sin ti