You can download the Movie Lens 100K dataset (for collaborative filtering) from http://files.grouplens.org/datasets/movielens/ml-100k/.
This dataset has movie ratings given by 943 users for 1,682 movies. These ratings are stored in the u.data file at http://files.grouplens.org/datasets/movielens/ml-100k/u.data. The full u data set has 100,000 ratings by 943 users on 1,682 items.
Each user has rated at least 20 movies. The users and items are numbered consecutively from 1. The data is randomly ordered. This is a tab separated list of:
user id | item id | rating | timestamp.
The time stamps are in Unix seconds since 1/1/1970 UTC.
The following C# program translates this data to an F# array so that this data can be fed to the collaborative filtering algorithms implemented earlier in the chapter:
https://gist.github.com/sudipto80/606418978f4a86fe93aa
Once you generate this array, you can then plug this into the algorithms described earlier.