Whole cone hops are generally added to the brew kettle in a compressed form because hops are dried and compressed into large bales after harvest and stored like this until use. Brewers who use whole hops cut open the bales and weigh out the amount needed for brewing. It is typical to see large clumps of whole hops being dumped into big brew kettles. When added to boiling wort, the hop clumps break apart into individual hop cones and the bittering and aromatic compounds are extracted during the boil. Whole hops are traditionally removed from wort with a hop back, a strainer resembling a mash tun prior to wort cooling.
When brewing smaller batches, whole hops can be placed in a hop bag or tossed in loose and strained out at the end of the boil. There is really no need to crush hops prior to boiling, although turning the whole cone into a powder does increase the yield of bittering compounds. When pellet hops are made, the first step of the process is to turn whole cones into hop powder and the second step is pelletizing. Pelletized hops typically have better hop utilization than whole cone hops, but the difference is only about 5–10% so doing this at home may be more trouble than it is worth.
You should be careful about boiling hops in a small wort volume, however. The maximum solubility of iso-alpha acids in wort is about 100 mg/L or about 100 IBU. Let’s assume you are brewing a 5-gallon (19-L) batch and want to boil your hops in a half-gallon (2 L) of wort. If your target for the whole 5-gallon (19-L) batch is 10 IBU, a very low bitterness level, you will be OK since the half-gallon (2 L) of 100 IBU wort when diluted with the 4.5 gallons (17 L) of wort without hops comes out to 10 IBU. But if you want to brew a beer with more bitterness, which pretty much means any style other than American-style lagers and wheat beers, you are not going to hit your target bitterness. Your best bet is to boil your whole hops with all of your wort. Hop bags are easy to use and inexpensive, or you can use a strainer. Whatever method you choose, enjoy those homegrown hops!