I got a question from a Youtube viewer about starting Ultramarines, so thought I would share my reply here. I think this is pretty sound advice for any new player. Or vet for that matter.:
Hey man,
Well I have been out of touch with Warhammer 40k lately with the rapid fire changes to the game. But falling back on the tried and true I can offer this advice.
If you are a new player, new to the game:
Buy the most up to date codex. I think the newest one is coming out on the 12.
Look through the book for pictures you like. Read the fluff for stories that inspire you. Enjoy.
Based on what you found in the codex, at the GW website and browse for the single Space marine model that you like the best, buy that model from your retailer of choice, and paint it. Don't fumble through the painting, search for one of the many many painting tutorials, including my own, get it, and use it. That will take away the learning curve and make you happier from the beginning and make the chances for you sticking with 40k higher.
Once you have that model done. Buy another. If your first was a tank, buy a box of infantry. Vice versa. Once you have completely assembled and painted that set. Rinse, repeat. DO NOT buy 900 dollars worth of box sets, and open them all up forming a huge pile of plastic, or even put them all nicely lined up on your shelf. This will cause you to lose steam. Buy a single box at a time, build and paint it then go to the next.
Once you have a couple of infantry and a couple of tanks, now your skills should be good enough to tackle painting an HQ model. Pick one and do so.
By this time you will have a small army consisting of an HQ, a couple troops, and a couple of tanks or other models. This will get you close enough to a 500 point list and playing your first game.
Once you have this small force assembled, NOW you can start looking at the rules. Look at the Force Organization chart. Look at formations. Do you see a formation from the fluff that you might like to emulate? I am sure the new codex will tell stories, then demonstrate a formation based on that story. Pick one of these formations, and then continue on with your collecting. Fill out the suggested models in the formation. Play games. If you are getting beat down, ask your opponent about your weaknesses. Buy new models to fill those weaknesses. Build and paint them.
Your goal is a 2k point army consisting of two formations. You can mix and match them, or take two of the same. Why 2 formations? I don't know, that is what I do. This is not a rule. It is a suggestion based on my experience. I am using 2 FLesh Tearears formations from the Blood Angels book.
There you have it! Notice how I didn't tell you any thing specific? That is on purpose. Any player in the world can tell you to go buy models based on their preferences and expertise. That doesnt mean those models will work for you.
What are strong units to play? Again, revert to what is fun to play. These happen to be both.
Vindicators are really cool looking and have a powerful cannon.
GW just released a brand new set of assault marines. They are a Space Marine staple. Get them.
Get a tactical squad. They are always useful.
Sniper scouts are cost efficient and surprisingly strong. I do reccomend several units of them in ANY space marine army.
Storm Ravens are among the strongest flyer, I don't believe that has changed lately. Plus they are cool, fun to paint, and carry other units.
Ironclad Dreadnought. Powerful, cool and fun. Put it in your Storm Raven.
The rest is up to you. Take this advice and go forth into your Ultramarine glory.
Let me know if you have any specific questions I can help with.
Jawaballs