I have been Orthodox for almost a year now, but Private devotions is a subject that was not covered in catachetical discussions. Yes, I understand the need to pray daily, morning and evening, read the scriptures and lives of the saints- but how? Is there any tradition(s) regarding private prayer being prayed aloud vs. silently; sung vs. said? How about physical postures? Facing East? Before you shower, or after breakfast? Are there different answers from different jurisdictions?
It all depends on what you're doing, and on your discipline level. That's why it's always best to make a plan with a priest, and stick to it, and build on it with some guidance.
When reading simple prayer services (like what you'll find in the Daily Prayer-type books/booklets), there isn't much there to be sung, so read is good; however, I wouldn't recommend reading them silently until you've done them hundreds of times. Speaking aloud engages more senses, which is a hallmark of Orthodox worship - you're not only committing the prayer to your memory and thoughts, but you're channeling them to your language centers and, since you're saying them aloud, you're engaging your hearing as well. Eventually, the prayers become a part of you (I pray that we all get to this point!), and the distinction between saying them aloud and praying them silently will melt away (it won't matter anymore).
As for timing, I've always found that first thing in the morning, or last thing at night, are the best times; we should say a brief prayer before every task we undertake, but for a "daily routine," it is best to either pray before doing anything (i.e. right when you roll out of bed), and/or pray when everything is done (except sleep). This would parallel the Orthodox worship cycle, which has prayers at the earliest hour of the morning (Matins/Orthros), and the latest hours of the evening (Compline).
You may indeed find different answers coming from folks of different jurisdictions - but the right mix will be unique to you, which is why consulting with a priest on this is a good idea. You don't want to start off with too much, for if the cycle gets broken it will be too easy to not start it again; if the cycle is too light, then you're not utilizing your potential adequately. Go to your parish priest, or another priest you trust; if you don't have any priest with whom you have a close relationship, then attempt to build one. Heck, I'd even say to enter into a dialogue with one of our resident priests here (we have many on the site, in case you didn't notice); each one will not only be willing to build a relationship with you, but each one has the familiarity with Orthodox prayer life to help you get started with a good routine.