1. Introduction
2. Sample
2.1. Selection
2.2. Properties and Evaluation
3. Observations and Results
3.1. HIFI
3.2. PACS
3.3. Ground-based Follow-up
4. Outflow Characteristics and Energetics
4.1. Low-J CO Emission
4.2. HIFI Water and mid-J CO Emission
4.3. $I O_{I J}$ Emission
4.4. Mass Accretion vs. Loss
4.5. On the Difference Between $I O_{I J}$ and CO
5. Envelope
5.1. HCO+ vs. $H_{2}O$
5.2. Infall Signatures
6. Evolution of Water Line Profile Components from Class 0 to Class I
7. Summary and Conclusions