Angels are pretty cool to work with, from what I know they are beings on love and light. A guardian angle, is said to look after and protect their person. However, most cannot interfere with the person life, unless it is a near death situation. If you wish to work with them, than learn as much as you can about them, from different sources. They will give you hints in the form of feathers that they are near by.
Archangels are a little bit different and something that I don't fully understand myself, just yet, but from what I know, anybody can call upon a Archangel help. With just calling by their name, each Archangel has their own job that they are good at. For example Archangels Michael, will come to you at once, if you need protection, he is good, at cutting out negative people in your lives, and is said to be around. Whenever you may feel warm, or see blue orbs of light.
It takes a lot of energy for them to appear, that isn't a dream like or a trance like state. Due to different vibrates. I don't think they will have a problem with working with you, they are known to look at things with love and light, and come from a place of no judgement.
However, much like everything angels are not what Hollywood may show them as. There is a reason, why Archangel Michael, holds a sword and a shield, some are warriors of light and should be respected as such. They don't necessarily have a certain offering that they enjoy, at least not that I know just yet, but a simple thank you. You can work with crystals as will if you wish, sun stone comes to mind.
I've shared this link before, but because I think it has some great information that really does clear up a lot of confusion. Be aware that the guy behind it does do card readings, so his adds might be a bit annoying, but his information is pretty great.
Talks about Angels as will, and some subject she brings up I have not ran into anyway else. Like waring signs are pretty handling.
And this site goes into detail about the different Archangels out there.
I mainly work with them through the use of oracle cards. Their normally the first to warm me, if there is something on the way that doesn't mean me will, by the form of different feathers. I normally know that they are around, whenever I get gooses bumps on my skin, when working with the cards.