TN Manoharan = Girish Ahuja(both are equally good, Girish Ahuja has simple language so that you can understand concepts and solve questions youself, wherelse TN Manoharan has huge no. of solved questions, some people understand more my illustration, fot them Manoharan is suitable) Choice is yours
VK singhania's book is only needed if u want to do Phd. in taxation
NOTE- My IPCC attempt is in Nov 2012, so I have not gone much into detail of the book though I have read intial pages of both the book, I have no idea which is better book when the chapters get harder.
For new readers I will suggest Girish Ahuja because of its simple language, but since you have already read the bible i.e Singhania, TN Manoharan will be a better option for you, anyways the choice is yours.