Well if you ask me there are many of them.
This here on Tripoto is a great place to discuss things and receive genuine suggestions.
Plus, there are many travel and himalayan groups on facebook. But they have a long process of even posting your query.
Yes you can do it all by yourself.. but there are chances that you divert from path.. for that you can accompany the fellow trekkers.. carry adequate water , nuts, tents, good quality sleeping bag, dry ration , also micro spikes wud be helpful, if a regular trekker ,then you can purchase gaiters to prevent your legs from snow. Also check before you go for the permissions required as the forest officers do not allow the outside to trek on there own without any local guide. all the best.
Can't say about hostel, but if you are looking for a decent hotel at a budget price, look for 22-suits near margao. I had a wonderful experience there.