I've played the Sveshnikov on and off for years.  The problem is that there is no real book which tells you the main plans like say Tony Kosten's book on the Nimzo did - it just isn't that sort of opening.  The positional themes all hand on tactics more so than in any other opening that I've played before.  There are ideas e.g. fighting for control of d5, sidelining the white Na3, kingside attack , b pawn sac for the centre etc etc.  However, you have to calculate deeply.  Just playing based on plans is a recipe for disaster.  As it is positionally risky and sharp the consequences of a mistake are apparent much quicker and quite often fatal.  I'd go with the Easiest Sicilian and practice.  My last season I scored 5/6 with black.  The loss a blunder from a better position (which i had obtained by understanding that he had to prevent me sealing the queenside, but he didn't realise is and let me) against a higher rated player - I never followed general plans....just calculated and used experience.

Well, you know, there are various books on it, there is Chesspub, NIC Yearbook, Informant, CBM ...

The thing is, when I see things like (a) asking "what needs to be improved?" about a game in which Black lost a valuable tempo in the opening and then appeared to hang a piece to a two-move tactic a few moves later, and (b) a suggestion to approach opening study by dividing the board in half, it makes me think you may be missing the mark in being concerned with the latest Sveshnikov theory.  (I'm reminded here of Loek van Wely speaking in 1996 about the, in his view, over-developed opening knowledge of many Dutch youth players:  "Take the Sveshnikov Sicilian.  Even with my rating, I hardly understand it.")