You're wasting your time looking for 'chain' hotels in Spain. The few that we have are located in industrial centres, near airports, etc.
But the comments above are all correct, one of the great things about travelling in Spain is the range of good value, family run hotels and '
hostals', and more and more '
casas rurales' which are a bit like farmhouse B&Bs.
The system is a bit arcane if you are not used to it, so I explained all the
details on my blog.
For on-line reservations,
booking.com* is really well represented and in general you can trust the reviews - unlike TripAdvisor, whose reviewers just talk about themsleves!
Regs
Simon
* I've put this link to 'my' booking.com - as an affiliate I get a minuscule 'commission' - it would be all the same to you - as I too am poor!