Resource tiles are a good way to gain rss when you need a lot of something and don't have enough stored or in your Back Pack
images forthcoming for tile types
The number will tell you the top limit of what might be there. Many times, people leave scraps (i.e. 30k resources when there were 300k). This is considered bad form, as it needs cleaned out to spawn a new resource tile.
When harvesting, the safest way is to send your lowest level troops to gather. It's always good to carry at least some troops a tier lower than your top tier solely for harvesting. For example, if you are at Tier 2 troops, don't dismiss your tier 1 troops to make room. Use them to harvest so there is no loss if they are attacked.
The safest plan for farming resources from tiles is to use Tier 1 troops, while having your hero equipped with farming gear. (Army Capacity) read more about farming equipment on Equipment page. There is also using your higher tiered troops, such as Tier 3 with travel speed gear equipped. Use this loadout at your own risk, tile hitting is not an uncommon event.
All resource tiles have a % chance to spawn a materials used in the construction of hero equipment. Different types spawn different materials. The level of the tile governs how much rss is available but has no effect on the % chance to get a material but it does slightly increase the % chance of it being an enhanced material at uncommon to legendary grade. Some people claim to have got gold materials from Level 1 tiles but people also claim to have seen Nessie and big foot.
NOTE: Taking over an occupied resource tile is an act of aggression. Refer to the Rules of Engagement to determine if it makes sense. Do not attack a resource tile unless you are prepared for a guild war. If you are attacked, unless you know you can handle it on your own, report it to the guild so we can mobilize and protect you.