It is essential to drink some water after your session. This helps flush out the toxins that have been released from your musculature as well as rehydrate and nourish those muscles.
It is not uncommon to feel some soreness between 1-48 hours after your session, after which time you should notice considerable relief from your problem. How long that relief lasts will depend on a number of case specific details, which your therapist can discuss with you.
Because Massage Therapy has a cumulative effect, you should experience relief for a longer time after each session until the pain or restriction no longer exists.
Your therapist may give you some stretching or an exercise routine to carry out between treatments. Doing these consistently will keep your muscles loose and will help to speed your recovery time.