Living In Spain - Experiences or Resources?

Before you get fully loved up on this idea - are you aware of the Schengen agreement?

.......and the 90-day limit for staying within the Schengen zone (most of western and central Europe) as a tourist, without a long-stay visa or EU passport?

There are a variety of publications designed for "ex-pats" rather than "tourists." I haven't been reading any of those lately, since it's not our focus in this office.

David, you don't say what your nationality is. It would be useful if you filled that in on your profile.
If you are not an EU or Schengen Area citizen, you will, as Laura says, require a visa to stay more than 90 days in the Schengen Area (which includes Spain). Depending on your nationality you may need a visa even for those first 90 days.

Are you planning to work in Spain, or just live on money you already have? If you are planing to work (including working remotely and being paid from your home country), then you need a working visa, and you need that from day 1. The "90 days in 180" allowance is only for tourists, that is people who survive on money they bring in from outside and do not work.
Getting a visa will not be easy, you need to contact your local Spanish Embassy. Getting a work visa is even more difficult, you usually need to get a job first, and the employer has to prove he couldn't get a local to do the job.

You also need to consider health insurance, including for your daughter.
And, if you become a legal resident, you home Driving Licence will no longer be valid and you have to pass a Spanish driving test.

As for finding places to live, where in Spain are you planning to live? It is a big country. It would be best to make a pre-visit as a tourist and research what is available.

... then I also strongly suggest you get a bit of background on "Spain" because it's not a country in the traditional sense... while basic legislation might be common in all of the territories, there is little uniformity in everything else and in a lot of aspects of 'daily life': seventeen autonomous governments with different degrees of self-government (for you, it means that certain 'rules' might be different depending where you end up landing...) and, more importantly, there are four distinct cultures with four different languages (Spanish, Basque, Galician, and Catalan) and although Spanish is supposed to be a 'common' language, you will certainly need to learn the local language if you really want to 'be part' of wherever you end up living. Quite often, expats say that these feel like different countries.

Just pointing out so you take that into consideration.