The WCCM School of Meditation offers lots of free and pay for resources about mantra-based 'Christian Meditation' as taught by John Main. It also offers on line courses, books/audio books, DVD's and links to WCCM programmes in 60 countries.
On line meditation
The WCCM on line meditation group site lists numerous groups that you can link with to meditate on line together. Most in English, but also groups that run in Spanish, French, Italian and Portuguese.
WCCM's Soundcloud archive holds nearly 1,000 different talks relating to meditation that have been part of WCCM events. This amazing resource, with many well-known speakers, is free to listen to and well worth exploring.