Jasper was a little day/night confused at first, which I believe is pretty common, as babies in the tummy tend to sleep during the day while your active and then be more active duriong the night when your sleeping - tricky little bubbas!
This WILL correct itself with time.
My tips are during the day go for walks in the sunshine and fresh air, it feels great for you to get out of the house, but it also I think gives them a bit of an idea of what 'day time' is supposed to look like. At night keep her room COMPLETE dark, no night lights or anything, when you feed her at night time turn on only enough lights to be able to see her - like the hallway light, or a lamp, rather than her/or your, depending on where she's sleeping, room light - feed her without talking to her or making eye contact, as if she thinks you're willing to talk and play she wont want to go back to bed..
... the next bit is up to you and I only started doing it when Jasper was 8 weeks, because I didn't have the heart to when he was really little... swaddle her up nice and tight and pop her back to bed and let her self settle, even if she has to CIO for a minute or two... otherwise just rock, pat, sing, whatever you do to settle her to sleep.
I personally cant get over how magical its been since Jaspers been self settling, the first week he cried a bit, but now he's able to self settle, with only a few shouts of protest as he's swaddled and put to bed - he's almost always asleep within 5 minutes *touch wood!*
Mind you, all this is just MY experience and how Jasper has responded, see what feels right and works for you!
Also... as for books... books I think are good resource for reference if you want to know something specific or if you want to have a ballpark figure about how much sleep your LO should be getting... tips for settling...etc... but... take the information you read with the same scrunity you would if someone you dont know gave you verbal advice, because just because its written and published, doesn't make it true!