how to create dataset for classification and pattern recognition (neural network)

Dear all I have a table of extracted features from the image. I need to create a dataset to use it in classification and pattern recognition. I have many images and i will group them according to disease stage to 4 or 5 groups or classes. could you help me how to create the dataset (inputs and targets) and if there some advice to create a good classifier and have a good results. thank you