The 7th edition of the Warhammer 40k rules have favoured the Chaos Space Marines. The Maelstrom of War missions are forcing the gun line armies to come out from behind their bunkers and give close combat armies like the Chaos Space Marines a chance. Another strong area that the Chaos Marines can take advantage of is the use of psychic powers.
Across many of the Chaos Space Marine units you will see that you can take different Mark of Chaos upgrades. These upgrades are not prices of equipment, but skills bestowed from the Chaos god that the Chaos Space Marinesfollow. In many cases you do not have to take a Mark of Chaos. They are totally optional. However they do not come free. Each mark will have a points cost associated with it, and you can only have a maximum of one mark per unit. If you are new to Warhammer 40k then I would suggest that you leave the Mark of Chaos skills for now and revisit them after you have played a few games.
If you are looking to use these upgrades in your army list make sure that you know what benefits the Mark of Chaos give your units and choose a Mark that fits in with your over all game tactics.
A suggestion that may help here is to write out the units details on a 4×3 index card, using one card per unit, so that you can refer to the units stats and skills quickly during the game. This will mean that you will be more likely to remember any special rules the units have and this in turn will mean that you will not be waiting points on upgrades that you do not use.
One thing that you do need to be aware of is that characters with one mark of chaos can not join a unit with a different mark. So for example a Tzeench Chaos Lord can not join a unit of Khorne Berserks. This is important because it limits the ability of a character to hide it a unit of troops if the units have the ‘wrong mark of chaos’.
There is no doubt about it. The Chaos Space Marines are configured to be a close combat army. What you will be looking to do is get in to close combat as quickly as possible. However remember that some of the armies out there are even better at close combat than you are, so having a plan that can adapt will be the best option.
One difference between the Chaos HQ choices and the Imperial Space Marine HQ choices is that the Chaos HQ units do not get command squads and transport options. Banner bearers are replaced by personal banners that the Chaos HQ can take. The apothecary is missing though, so I hope you are not needing first aid!