Fast Artificial Neural Network Library

The Fast Artificial Neural Network Library (FANN) is a good way to get started with neural networks.

Fast Artificial Neural Network Library is a free open source neural network library, which implements multilayer artificial neural networks in C.

The web page is here. The documentation contains some simple example which illustrate how to train and test a neural network. Cascade training is a useful feature, where neurons are added during training, which means that users don't need to determine how many neurons and hidden layers should be in the network before training.