These tips I have received from ogame-tips@aweber.com on behalf of Robert.
I hope you find them to be useful:


Resources insight

Generally, you need all types of resources. Without resources there
is no OGame. There are 3 types of mines for metal, crystal and
deuterium and fourth valuable resource is energy.

Lets see a few details about them.

1. Metal - metal is the cheapest resource and you will probably
have enough of it most of the time. When you start raiding and get
over higher technology research levels you may find yourself with
huge stock of unused metal. Anyhow, metal is important for all
buildings and especially for your fleet amour (Armour technology
uses pure metal in enormous amounts). Sometimes, depending on your
building priorities, you may suffer lack of metal but it is not to
hard to catch on requirements.

When you start a new planet from scratch you will easily see that
metal is most important to set up your mines. You need metal to
build metal mine. But you also need metal to build solar plant
because your metal mine will not work without energy. Sometimes it
needs good decision if your only options are to upgrade solar plant
or metal mine. If you upgrade solar plant you will get the energy
but your metal quantity will drop and you will need to start from
the beginning. Other way, if you spend metal to upgrade metal mine,
you will get more units per hour but you will go deep in red area
for energy so your metal mine will be slow and will not work in
full capacity. So choose wise and use calculator if needed to se
what option is quicker to set things up for further development of
another buildings.

2. Crystal - crystal is mostly needed for your researches, because
it is used to develop electronic technology, computers,
communications, and all kind of tech upgrades and also for large
ships. Crystal mine is more expensive then metal in the same level
and is produced slower then metal. You cannot start successful
raiding without crystal as it is used for constructing you first
small cargos (those are your hands), and also espionage probes are
built from pure crystal (and those are yur eyes). On higher level
you will often find yourself sparing crystal for some important
research or building your first colony ship. It is recommended to
act fast when you are sparing or raiding for crystal as large
amount of it makes you interesting raiding target to other players.
Try to collect it in one online session and start to build what you
want to build so you can get rid of the stocks. Crystal is also
important in early game when you setting up you basic income as it
is used to build other resources buildings though.

3. Deuterium - it comes deep from the sea. It is the most expensive
resource and its production is slowest. Deuterium indicator on your
top OGame bar will be on very low levels most of the time.
Deuterium is mostly used in researches and pure deuterium is
inevitable for your fleets to move, as fuel. Also you will spend 10
units of it for every solar system that you are lurking at in
galaxy view. In the early game, when you are low on deuterium, type
direct coordinates of solar system in your galaxy position
indicator (where you stopped last time) to spare some of it.

Deuterium is main resource that will cause your development
stagnation from time to time. Since it is rare you will hardly get
some significant amounts of it when you are raiding through your
neighborhood. So be smart with it as it is valuable. Specially be
careful when you are collecting deuterium for some important
research. Any significant amount of it standing around will make
you most desirable target in universe. So, if you are not able to
firmly defend your spared amounts, use it in one breath to start
building, researching or whatever else.

You should also know that the hottest planets are closest to the
sun (lower positions) and gives smaller amounts of deuterium. The
farthest and coldest give much more for deuterium for the same
level. Think of that when it comes to establishing a colony.

4. Energy - yes, without energy you may shut down your computer,
there is no place for you in OGame (even your computer wont work
without it). There are three ways of producing energy: solar
plants, solar satellite, and fusion plant. All of them produce
different amount of energy. Your indicator on the top of the page
shows energy used/energy available, so if it turns red it means
that all your facilities try to use more energy than you have
available in total. This will cause your production to drop down
and production will go slower, like as your mines are few levels
lower. In this case you must develop more energy production plants.
Every new level on any of resource mines ask for more energy to
produce.

Lets take a look at all of the plants.

Solar plant produces the most of your energy and are first
available when you start from scratch (and also does not need
deuterium to build). The bad thing is that they becomes extremely
expensive from level 15 up so you should always ask yourself if it
is worth to upgrade them in particular part of the game. Anyhow,
level 15 gives you descent amount of energy if you base your
strategy on raiding.

Solar satellites are you auxiliary plants. They use solar energy
and are placed in your planets orbit. They produce more energy on
planets closer to the sun. T calculate an amount of energy from
your solar satellite look for an maximum temperature on your planet
(overview screen) divide it by 4 and then add 20.

Solar satellites are practical in late game when you need huge
amounts of energy for researching graviton technology. They are not
so expensive but are very vulnerable and have no defense. Your
solar satellites will mostly be destroyed in attack so you will
find yourself deep in red area. Don't depend on them in the early
and mid game.

Fusion plant is rather practical plant based on nuclear technology.
It uses deuterium to convert it to energy. Higher levels ask for
more deuterium consumption. You can use them as regular energy
plants if you are willing to pay deuterium price. It is not bad
idea to have them developed to some level when you have some extra
resources but it would be good if you manage to have all your
energy from solar plants and fusion shut down (just for emergency,
if you need to rebuild after some serious attack)

Conclusion: your complete economy depends on resources; you need
good planning on your upgrades to get maximum efficiency. On
raiding, pick the targets with some amount of deuterium, as it is
even worth to fight for some larger amounts. No worth to fight for
metal. Use resources page to adjust the amount of production when
you are in need for specific resource but you don't have enough
energy. Try to shut down your fusion plants without going to red
energy value, as this will spare you deuterium. When you get to
recyclers use them often to collect debris's, they have lots of
metal and crystal to pick up and no one will be mad at you, as they
will not know you were there. Note that recyclers are so slow that
you need to check the debris often to see if someone didn't sucked
them before you, so you can recall recyclers back on time.

Thank you for reading and keep those mines rolling.

EDITORS NOTE: Here are several links that may help you understand
some of the terms or techniques outlined above:

Using Fields Wisely
- http://www.ogametips.com/21/using-fields-wisely

Solar Satellites
- http://www.ogametips.com/26/solar-satellites


Want even more OGame Tips and Strategies?

Check out our exclusive OGame Tips Strategy Guide
- http://www.ogametips.com/strategy-guide/