That's a pity, it seems a shame that anyone might miss out on such a fundamental part of art practice when it's so easy to organise.... Simply collect enough interested people to hire out a space (or get it free if your council has such a policy), find a model, agree on a time, location and fee and you're ready. Sometimes art supply stores might give you a discount of low quality cartridge or bond paper so the class can quickly churn out as many sketches as possible. Although initially people may just be working from visual diaries. Once you have enough funds you might be able to purchase mdf board cut to size that you can use to mount larger sheets of paper, it is better to work large and with charcoal for speed.
Anyway, here's a tut I found useful for getting around Lineart in paint tool sai:http://suzuran.deviantart.com/art/Linea ... -134457330
Digital is still largely unknown territory for me, so I found Sai a very useful tool. Vector and bitmap in one at a reasonable price.