I love
The Imitation. It's one of my favorite books. It is somewhat geared toward priests and religious, though, so you should keep that in mind. It's fairly obvious when he's speaking specifically to priests or religious.
I don't mean to harp on it, but
Intro to the Devout Life by St Francis de Sales is the best book I know of for people seeking holiness in the world. It's very practical. He also has lots of letters of spiritual direction written to people in the world. You can find a good number of these for free online on google books.
The Imitation and
Intro can both be found for free online here:
http://www.catholictreasury.info/library.php and probably many other places online as well.
Abandonment to Divine Providence is good, which is also on that site, and I am also very fond of St Alphonsus' 50 Maxims of perfection. That might not be quite what you're looking for but it's very good, helpful, and practical. I'll reproduce it below:
Quote:
1. To desire ardently to increase in the love of Jesus Christ.
2. Often to make acts of love towards Jesus Christ. Immediately on waking, and before going to sleep, to make an act of love, seeking always to unite your own will to the will of Jesus Christ.
3. Often to meditate on his Passion.
4. Always to ask Jesus Christ for his love.
5. To communicate often, and many times in the day to make spiritual Communions.
6. Often to visit the Most Holy Sacrament.
7. Every morning to receive from the hands of Jesus Christ himself your own cross.
8. To desire Paradise and death, in order to be able to love Jesus Christ perfectly and for all eternity.
9. Often to speak of the love of Jesus Christ.
10. To accept contradictions for the sake of Jesus Christ.
11. To rejoice in the happiness of God.
12. To do that which is most pleasing to Jesus Christ, and not to refuse him anything that is agreeable to him.
13. To desire and to endeavor that all should love Jesus Christ.
14. To pray always for sinners and for the souls in purgatory.
15. To drive from your heart every affection that does not belong to Jesus Christ.
16. Always to have recourse to the most holy Mary, that she may obtain for us the love of Jesus Christ.
17. To honor Mary in order to please Jesus Christ.
18. To seek to please Jesus Christ in all your actions,
19. To offer yourself to Jesus Christ to suffer any pain for his love.
20 To be always determined to die rather than commit a willful venial sin.
27. To suffer crosses patiently, saying, "Thus it pleases Jesus Christ."
22. To renounce your own pleasures for the love of Jesus Christ.
23. To pray as much as possible.
24. To practice all the mortifications that obedience permits.
25. To do all your spiritual exercises as if it were for the last time.
26. To persevere in good works in the time of aridity.
27. Not to do nor yet to leave undone anything through human respect.
28. Not to complain in sickness.
29. To love solitude, to be able to converse alone with Jesus Christ.
30. To drive away melancholy.
37. Often to recommend yourself to those persons who love Jesus Christ.
32. In temptation, to have recourse to Jesus crucified, and to Mary in her sorrows.
33. To trust entirely in the Passion of Jesus Christ.
34. After committing a fault, not to be discouraged, but to repent and resolve to amend.
35. To do good to those who do evil.
36. To speak well of all, and to excuse the intention when you cannot defend the action.
37. To help your neighbor as much as you can.
38. Neither to say nor to do anything that might vex him. And if you have been wanting in charity, to ask his pardon and speak kindly to him.
39. Always to speak with mildness and in a low tone.
40. To offer to Jesus Christ all the contempt and persecution that you meet with.
41. To look upon [religious] Superiors as the representatives of Jesus Christ.
42. To obey without answering and without repugnance, and not to seek your own satisfaction in anything.
43. To like the lowest employment.
44. To like the poorest things.
45. Not to speak either good or evil of yourself.
46. To humble yourself even towards inferiors.
47. Not to excuse yourself when you are reproved.
48. Not to defend yourself when found fault with.
49. To be silent when you are disquieted.
50. Always to renew your determination of becoming a saint, saying, "My Jesus, I desire to be all Yours, and You must be all mine."