(This one is focused on technology choices and approaches)
If you want assured success and have a budget, pick Oracle. It continues to meet every need in the DW space.
If you are one of the largest organizations and are handling trillions of records, you are probably already on Teradata.
Netezza is also there. I have never tried it myself.
Some new cloud platforms are interesting, such as Snowflake. I have never tried it but I see it in cutting edge organizations.
Cognos is great as an enterprise reporting technology, but some other vendors are more nimble.
The leading one amongst this for visualization innovation is Tableau.
Business Objects and OBIEE are other good options for enterprise reporting.
Qlikview has its niche.
Looker seems to come up now and then as a cloud based new offering.
Informatica has the most market share and I would pick it over others for its versatility.
Ab Initio is the fastest I have ever seen.
Talend is not bad but not sure of its heavy lifting skills.
Use Inmon for the ODS and Kimball for the Data Mart(s).
Don’t bother with SCD Type II – it is dated and not the most efficient way to track changes.