Here's my worthless contribution...
1. What this Dharma Door practices is mindfulness/contemplation of the Buddha (choice of any Buddhas/Bodhisattvas like Amitabha, Bhaisajya-guru, Avalokitesvara, Manjusri, Maitreya and et al) and continuity of one's practice in an assured and non-retrogressive environment towards the fruition of ultimate Enlightenment in an expedient Pure Land of a Buddha, this is a wonderful expedient of a Dharma Door utilising existence towards realising wisdom & emptiness in Mahayana Buddhism.
2. When 'Pure Land' is mentioned, the most common/popular notion that comes to mind would be Amitabha Buddha and His Sukhavati.
3. The concept/aspiration is:
a. where excellent and conducive conditions of an expedient Pure Land have its source from realised vows and perfected practice of a Buddha as opposed to the current triple worlds of endurance (desire, form & formlessness: having its source from defiled karmic retributions of sentient beings) subject to conditions of turbidities and uncertain retrogression that sentient beings are currently in,
b. of continuity of one's current practice in an aspired Pure Land of a particular Buddha that one practices on,
c. the main target of being in a Pure Land is for the assured fruition of ultimate Enlightenment, both for oneself and all sentient beings in one lifetime there.
4. Resources here
a. first make your choice here
b. then choose those listed as the Pure Land Tradition
i. under the Chinese, Korean, Vietnamese Mahayana and Japanese Jodo Shu/Jodo Shinshu Traditions
ii. OR those traditions which are listed earlier who also have the option of practicing dual Dharma Doors of Ch'an-Zen/Hua Yan & Pure Land
iii. OR if you are interested you can also check out any proper Tibetan Vajrayana centre and ask them on Pure Land practices.
c. you can also check out with one center/temple and see if they know/network with other affiliated Pure Land centres / temples as the online ones are sometimes not updated or have dead links and so forth.
If not, is that going to be a huge problem?
Not really if one have an aspiration and practice that is consistent and firm based on the Teaching and Discipline.
Whilst the Pure Land door is free from obliging one to a binding relationship with a teacher like in the Vajrayana context, online learning (in these days which have great resources) can never replace the benefits of having real life like minded worthy spiritual companions and a proper guiding teacher (besides having one's own resolute and consistent practice) which is what a center / temple is for. The ancients back then and some from today's generation are also known to make great strides and go out of their way at least twice a month or so just to be in communion with a community of practitioners for the sake of the spiritual well being and check and balance. One can utilise online learning until one's current impairing circumstances for whatever reason have improved and are more conducive and then move on to having fellowship with a real life community.