Currently there is no tab in INSPIRE that leads to the Data collection, but you can access it here. In the new version of INSPIRE, (now under testing at Labs), the Data collection will be as easily accessible as the other collections.
See the metadata table for specific MARC tags used in Data records.
DOIs, authors, collaboration, experiment, title, description/abstract, keyword, and date information are cataloged as in HEP records.
A few fields are specific to Data records. 336__t is the data type, in most cases DATASET. To connect a HEP collection record to a Data record, the recid of the HEP record goes in 786__w. The collection is input as 980__a:DATA
HEP records can also cite Data records in the 999C5 record as with any other reference. Mostly this is done either through a doi if available (999C5a:10.15484/milc.asqtad.en05b/1178157) or a recid (999C50:1269122).