Congratulations on playing Viking Age!
Here are some tips and advice to start you on your way to becoming a Master Viking! This assumes a VIP 0 player.
First task is to get Hilde and Vigdis – should be straightforward. After that get Gunnar for 40 armbands.
Do not spend your early reserves of odinite. You need a healthy reserve later on when upgrading your heroes from ordinary to excellent.
Do not combine skill tomes until daily tasks are unlocked. When they are unlocked, combining skill tomes once per day makes it much easier to get 200 points (and hence 10 gold bars).
If you want a high rank in the arena you might consider upgrading Hilde to excellent first and then spending all your skill tomes on Ursa Guard. Ursa Guard is currently highly overpowered in PvP due to its rate of activation.
If you are into a good PvE skill - then you should upgrade either Vigdis or Gunnar since their skills are quite good in PvE.
Early in the game, use your starting gold to buy 3 or 4 boxes (12 for 27 gold) of research guides when they are in store. You will need them come level 20 - otherwise you can't upgrade towers any further.
Level up your heroes in blocks of 8 hours costing 1900 silver since this is the most cost efficient way. Do NOT buy the 2nd training slot since you can't afford the silver for two heroes training at once.
Save your marching tokens until you have beaten the last swamp stage on cruel mode - then use your marching tokens to farm research guides (up to 7 a day).
Buy a daily gold apple for 2 gold - this gives you 40 extra spirit and the materials and silver you get from it is amoungst the best rate in the game.
Feed the dragon daily for 2 gold - this gives you more silver and higher income of silver in future.
When you get to level 22, silver should be your bottleneck resource and there will never be enough of it. Spend your gold on absolute plunders if it exceeds 50. When absolute plundering, only stop when you get lucky or run out of plunders since this maximizes the chances of you getting a lucky strike.
Towers and upgrades
Your first tier 4 tower should be multi-catapults. Early on you'll need to deal with mobs and flying creatures - this is an ideal weapon for both. Extend it when necessary so you can continue to sacred mountain.
Next tower upgrade should be Master Dragon Tower with Explosive shot. This is necessary to defeat the last swamp stage on cruel mode. Extend it when necessary until you can defeat the level. If you are having real trouble defeating the level use the free god's stone from the first world. This is a must-win level since it drops research guides.
Earlier we would have suggested you buy the Altar of Storms with Chain Lightning. Its effectiveness has however been decreased. Some levels on cruel do however require you to have mage towers. The best option for you would be to buy the Altar of Witches, and go for the Toxic Cloud skill.
These three tower upgrades should get you well into the game.